I encountered this problem only on the newest version, 2.20. At 99% the download paused, because the log said some piece was corrupt. I resumed the download and it completed. But when I opened the file it only was that part, that was download after the pauze. Seemed like the file was totally overwritten by the small piece of data. Do more users encountered this problem?
2011-02-08 16:13:16 +0100 torrent.c:478 [Fout] File1.mkv: Please Verify Local Data! Piece #787 is corrupt.