I've never heard that exactly happening, but I am aware there have problems with the ATI catylyst you are using.

Check out these links. http://www.gnutellaforums.com/showth...threadid=34408

and

http://www.gnutellaforums.com/showth...threadid=37538

you can also try fixes for LimeWire from this link.
http://www.gnutellaforums.com/showth...threadid=36420

not sure if they will help or not. let us know.