Comment 9 for bug 72142

A windows user with incident - http://talkback-public.mozilla.org/search/start.jsp?search=2&type=iid&id=26109651 - reported that disabling an extension called "My Global Search" stopped the crashing on exit. Apparently it appeared automatically after installing BearShare, and uninstalling BearShare didn't remove the malware.
References:

http://security-central.us/SafeHex/prevention.htm
http://research.sunbelt-software.com/threatdisplay.aspx?name=MyGlobalSearch.Toolbar&threatid=41891
http://www.file.net/process/mgsbar.dll.html
http://www.spyware-browser.com/items/-/9184/