Are you using anything like Norton Internet Security? Some of those anti-virus programs can cause problems with programs that connect to the Internet. Try disabling or even uninstalling the antivirus if you have one.
Edit: I see you already tried my above suggestion. What happens when you ping the IP address that mark posted?
Click Start > Type 'cmd' and press enter > Type 'ping 198.154.60.183' and press enter
I noticed that you mentioned none of the computers in your house can connect to Ixcoin. Are they all Windows 7 computers? It's possible that the problem may be with your router.
here is the result when i ping with ping 198.154.60.183
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\joyyen>ping 198.154.60.183
Pinging 198.154.60.183 with 32 bytes of data:
Reply from 198.154.60.183: bytes=32 time=267ms TTL=56
Reply from 198.154.60.183: bytes=32 time=271ms TTL=56
Reply from 198.154.60.183: bytes=32 time=266ms TTL=56
Reply from 198.154.60.183: bytes=32 time=286ms TTL=56
Ping statistics for 198.154.60.183:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 266ms, Maximum = 286ms, Average = 272ms
C:\Users\joyyen>
before i format my computer i have no problem getting blocks and connections but after i have format compute and installed win 7 then i cannot get any connection and block !
and i am using the same modem all the time !