It sounds like you folks are having problems with newdotnet.dll as mentioned in this forum:

http://www.gnutellaforums.com/showth...&threadid=2205

Have you installed BearShare recently with the newdotnet.dll add-on software? Some other file sharing apps include this silently so it could have been one of those. If so, read the above forum for ideas on how to get rid of the thing.

-greg