Did you check the file with Bitzi? There's a further link about Bitzi in the link I posted in post #2.
If you're seeing heaps of files where the download % regresses (even though you're not actually seeing the corrupted files message), have a look through this thread for ideas:
http://www.gnutellaforums.com/downlo...corrupted.html
If files show as ok with a Bitzi lookup, maybe one of your security apps or a firewall's having some effect?