See these for some pointers: 1. T3 Spammers 2. Quality of Content on the Network 3. Fake Movies & Why

My advice is related to point 1. Check bit-rate versus file size. If you can't do this, then if it's from a T3 source I'd be a little skeptical. You'll notice this happens with only the most popular (& generally newer files - particularly those that have been top of the charts.) Cable or modem sources ae usually quite reliable. T3's are not necessarily faster than cable/dsl. It depends on their upld bandwidth offerings & how many sources you can latch onto.

I've heard of another utility which can repair many also.

I think the emphasis the riaa/music industry has been placing on the gnutella network recently is becoming obvious with the much larger amounts of corrupt music files. There seems to be even more T3 sources now that do this. Be more-so diligent in your downlding I think is becoming a fact of life now dare I say it.