BigEd FWIW - Ebay has resolved issues like yours many times before. Your previous 100 positive feedbacks and the sellers 20 "busted" negative feedbacks would be a clear cut case to them. They will erase your negative feedback record and eventually terminate the scammers account. First step is the live Ebay help link. I've fended off a couple of scammers "potential negatives" before with their help. I'm at 166 positives, no negatives so far...
