Are you using 32-bit or 64-bit Java. Also, are you on Java 6 or Java 7? Lastly, where are you copying the rxtxSerial.dll files?
I use 32 bit Java 6, just copy the rxtxSerial.dll for your system to the same location as the java file.
It was the Bitcointalk forum that inspired us to create Bitcointalksearch.org - Bitcointalk is an excellent site that should be the default page for anybody dealing in cryptocurrency, since it is a virtual gold-mine of data. However, our experience and user feedback led us create our site; Bitcointalk's search is slow, and difficult to get the results you need, because you need to log in first to find anything useful - furthermore, there are rate limiters for their search functionality.
The aim of our project is to create a faster website that yields more results and faster without having to create an account and eliminate the need to log in - your personal data, therefore, will never be in jeopardy since we are not asking for any of your data and you don't need to provide them to use our site with all of its capabilities.
We created this website with the sole purpose of users being able to search quickly and efficiently in the field of cryptocurrency so they will have access to the latest and most accurate information and thereby assisting the crypto-community at large.
[2012-02-29 10:51:45,311] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 521 valid, 1 invalid (0.19%), 7 stale (1.34%), 361.74 (+-15.74) mhash, runtime: 104.48 min, idle: 0.08%, last: valid (336 ms)
[2012-02-29 10:51:47,168] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 522 valid, 1 invalid (0.19%), 7 stale (1.34%), 362.37 (+-15.76) mhash, runtime: 104.50 min, idle: 0.08%, last: valid (335 ms)
[2012-02-29 10:51:55,116] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 523 valid, 1 invalid (0.19%), 7 stale (1.34%), 362.59 (+-15.75) mhash, runtime: 104.63 min, idle: 0.08%, last: valid (666 ms)
[2012-02-29 10:51:59,894] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 524 valid, 1 invalid (0.19%), 7 stale (1.34%), 362.98 (+-15.75) mhash, runtime: 104.72 min, idle: 0.08%, last: valid (336 ms)
[2012-02-29 10:52:12,402] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 525 valid, 1 invalid (0.19%), 7 stale (1.33%), 362.92 (+-15.73) mhash, runtime: 104.93 min, idle: 0.08%, last: valid (334 ms)
[2012-02-29 10:52:28,511] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 00301e54 doesn't produce a valid hash.
[2012-02-29 10:52:34,323] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 2500ff00 doesn't produce a valid hash.
[2012-02-29 10:52:48,306] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 93b87f00 doesn't produce a valid hash.
[2012-02-29 10:53:06,535] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 08c81300 doesn't produce a valid hash.
[2012-02-29 10:53:19,106] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 75008700 doesn't produce a valid hash.
[2012-02-29 10:53:45,807] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ee461300 doesn't produce a valid hash.
[2012-02-29 10:54:03,581] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 4d008500 doesn't produce a valid hash.
[2012-02-29 10:54:20,150] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce c2fb4c00 doesn't produce a valid hash.
[2012-02-29 10:54:26,839] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ed000000 doesn't produce a valid hash.
[2012-02-29 10:54:36,564] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 794e5400 doesn't produce a valid hash.
[2012-02-29 10:54:45,851] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 5c006400 doesn't produce a valid hash.
[2012-02-29 10:55:14,850] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 33203500 doesn't produce a valid hash.
[2012-02-29 10:55:23,064] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 5e204100 doesn't produce a valid hash.
[2012-02-29 10:55:39,994] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce da517000 doesn't produce a valid hash.
[2012-02-29 10:55:42,161] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 7df2fe00 doesn't produce a valid hash.
[2012-02-29 10:55:56,825] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce d18c3100 doesn't produce a valid hash.
[2012-02-29 10:56:20,509] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 6f179200 doesn't produce a valid hash.
[2012-02-29 10:56:32,809] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 87fb6c00 doesn't produce a valid hash.
[2012-02-29 10:56:32,894] [INFO] [rg7.rg7miner.SubmitMngr$Submitter][port=COM4]: LP, 526 valid, 19 invalid (3.56%), 7 stale (1.33%), 349.18 (+-15.12) mhash, runtime: 109.27 min, idle: 0.08%, last: valid (666 ms)
[2012-02-29 10:56:48,537] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 4f909d00 doesn't produce a valid hash.
[2012-02-29 10:56:59,217] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 0000a700 doesn't produce a valid hash.
[2012-02-29 10:57:07,135] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce f7002700 doesn't produce a valid hash.
[2012-02-29 10:57:09,428] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce beab6b00 doesn't produce a valid hash.
[2012-02-29 10:57:21,042] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 80a10500 doesn't produce a valid hash.
[2012-02-29 10:57:29,757] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce af94d500 doesn't produce a valid hash.
[2012-02-29 10:57:37,361] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 63f9f800 doesn't produce a valid hash.
[2012-02-29 10:58:00,753] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 6bcbf800 doesn't produce a valid hash.
[2012-02-29 10:58:18,696] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 79435e00 doesn't produce a valid hash.
[2012-02-29 10:58:31,269] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce b5b7e100 doesn't produce a valid hash.
[2012-02-29 10:59:44,969] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 55121f00 doesn't produce a valid hash.
[2012-02-29 10:59:56,393] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ab608e00 doesn't produce a valid hash.
[2012-02-29 11:00:11,020] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 8b115300 doesn't produce a valid hash.
[2012-02-29 11:00:13,588] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce d6746700 doesn't produce a valid hash.
[2012-02-29 11:00:21,287] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 29d2a800 doesn't produce a valid hash.
[2012-02-29 11:01:09,988] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce fb828900 doesn't produce a valid hash.
[2012-02-29 11:01:32,822] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 59f35400 doesn't produce a valid hash.
[2012-02-29 11:01:42,483] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce a705cc00 doesn't produce a valid hash.
[2012-02-29 11:02:09,531] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 93be5300 doesn't produce a valid hash.
[2012-02-29 11:02:34,071] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 57000000 doesn't produce a valid hash.
[2012-02-29 11:03:22,741] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 1194fd00 doesn't produce a valid hash.
[2012-02-29 11:03:34,380] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 0098e500 doesn't produce a valid hash.
[2012-02-29 11:03:42,672] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce e80dd700 doesn't produce a valid hash.
[2012-02-29 11:03:46,024] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce d2aadb00 doesn't produce a valid hash.
[2012-02-29 11:04:29,601] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 5866bb00 doesn't produce a valid hash.
[2012-02-29 11:04:35,063] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 896a9500 doesn't produce a valid hash.
[2012-02-29 11:04:42,816] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 0ff37f00 doesn't produce a valid hash.
[2012-02-29 11:04:51,215] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 00b2a400 doesn't produce a valid hash.
[2012-02-29 11:04:57,180] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 00914600 doesn't produce a valid hash.
[2012-02-29 11:05:06,265] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce a0a53900 doesn't produce a valid hash.
[2012-02-29 11:05:25,736] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 7112d700 doesn't produce a valid hash.
[2012-02-29 11:05:28,585] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 8ff02000 doesn't produce a valid hash.
[2012-02-29 11:06:45,830] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce f0ea9100 doesn't produce a valid hash.
[2012-02-29 11:07:19,109] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 58dcab00 doesn't produce a valid hash.
[2012-02-29 11:07:33,559] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 2a9b7000 doesn't produce a valid hash.
[2012-02-29 11:07:35,352] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 9632c200 doesn't produce a valid hash.
[2012-02-29 11:07:47,467] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce d0430000 doesn't produce a valid hash.
[2012-02-29 11:07:56,367] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 79e6f400 doesn't produce a valid hash.
[2012-02-29 11:08:10,113] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 662ab000 doesn't produce a valid hash.
[2012-02-29 11:08:16,528] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 851e7200 doesn't produce a valid hash.
[2012-02-29 11:08:20,791] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 0fbcba00 doesn't produce a valid hash.
[2012-02-29 11:08:23,843] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ac5a5500 doesn't produce a valid hash.
[2012-02-29 11:08:33,359] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ecc92b00 doesn't produce a valid hash.
[2012-02-29 11:09:00,847] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce d18ab000 doesn't produce a valid hash.
[2012-02-29 11:09:18,212] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce b29a7900 doesn't produce a valid hash.
[2012-02-29 11:09:30,809] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 442a3500 doesn't produce a valid hash.
[2012-02-29 11:09:54,724] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 2b0b3f00 doesn't produce a valid hash.
[2012-02-29 11:09:55,423] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 0c0b2b00 doesn't produce a valid hash.
[2012-02-29 11:10:06,092] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 3e000e00 doesn't produce a valid hash.
[2012-02-29 11:10:57,902] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 4572e600 doesn't produce a valid hash.
[2012-02-29 11:11:32,845] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 7290d300 doesn't produce a valid hash.
[2012-02-29 11:11:41,968] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 9f833700 doesn't produce a valid hash.
[2012-02-29 11:11:51,049] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 00e91f00 doesn't produce a valid hash.
[2012-02-29 11:12:00,843] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce eac72800 doesn't produce a valid hash.
[2012-02-29 11:12:13,740] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 9ce40000 doesn't produce a valid hash.
[2012-02-29 11:12:25,707] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 006de200 doesn't produce a valid hash.
[2012-02-29 11:12:50,061] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 70c0f600 doesn't produce a valid hash.
[2012-02-29 11:12:57,754] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce ea001a00 doesn't produce a valid hash.
[2012-02-29 11:13:15,827] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 1b0feb00 doesn't produce a valid hash.
[2012-02-29 11:13:30,013] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce eb68ad00 doesn't produce a valid hash.
[2012-02-29 11:13:31,728] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 3b342000 doesn't produce a valid hash.
[2012-02-29 11:13:43,648] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 23203300 doesn't produce a valid hash.
[2012-02-29 11:14:05,010] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 8fee0000 doesn't produce a valid hash.
[2012-02-29 11:14:09,505] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce fb9f4400 doesn't produce a valid hash.
[2012-02-29 11:14:10,168] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce de41c400 doesn't produce a valid hash.
[2012-02-29 11:14:20,014] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 00355d00 doesn't produce a valid hash.
[2012-02-29 11:14:22,131] [ERROR] [rg7.rg7miner.fpga.FPGAControl][port=COM4]: HW error. Received nonce 6dae5300 doesn't produce a valid hash.