OH Oh! Sounds like you have a virus that's going around the gnutella networks. May I advice 1. Stay away from files less than 2,000 KB (2MB), & 2. register at norbies site & he will help you solve your problem. He "is" an expert;
NorbiesWorld (click on link)
More general tips here
WARNING: Viruses on network you should be aware of! (click on link)