Conflicts maybe on the version you are using. See this thread:
http://www.gnutellaforums.com/showthread.php?t=53386

As for NOD32, open the Control Center (clik green/white icon in taskbar) & slect IMON, then Setup, & under the Miscellaneous tab, click the Edit button next to Exclusion. Click Add, & find the Bearshare exe in C:\Program Files\BearShare. Click Open & then OK you way out.

Might not be a bad idea to do so under the Exclusions tab under AMON as well.