X11 - Originally from Darkcoin. X11 uses the following for hashing, blake, bmw, groestl, jh, keccak, skein, luffa, cubehash, shavite, simd and echo. There are GPU miners for this which makes it more suitable, CPU only coins end up run by botnets, so GPUs are best to keep these away. Hirocoin will be the first conventional crypto coin to use X11, Evan put X11 to use in DarkCoin which offers to move funds around anonymously. Hirocoin offers no such feature and will be completely familiar with those who use other crypto currencies like Bitcoin or Litecoin.
Try -queue 0 -scantime 0-2 and lower intensity. Might help. I haven't been getting a lot of rejects so dunno, maybe latency.