I have noticed that every time I selectively download files from a torrent, pieces will complete downloading but will not write to disk. Even if I re-enable all files in the torrent the pieces will not write to disk. My temporary work around is to download every file in the torrent, however this is not ideal. This has been an issue for a long time and not cropped up in the recent betas. µTorrent build 27026 Windows 7 Pro SP1 x64