Hi,
With the information you have provided, there is not much of a suggestion I could provide. However,
1) did you check if your antivirus (if it has a firewall) is configured to block certain programs and u were using that program?
2) Or do you have any other netlimiter program installed?
3) this is pretty dumb, but hey you dont know... it sometimes might be the issue.. do you connect to both the systems (for ex: using a splitter) or using a router?? If so, try and see the configuration for those.
4) try and install all updates released after sp2 if u haven't. It might fix your troubles.
I will update in case I think of something else.
BTW, Please title your query properly so that it would help others.
@Khattam, your reply to this post and your signature are kind of interesting (just kidding)
legolas.