For any reason when a seed have been stopped once, Transmission starts to download ALL of the torrent once again, even as the whole downloaded material is playable like any 100% d/l'ed files.

This also means that older fully downloaded torrents can't be reseeded, as the download starts from the beginning. Ergo, Transmission can seldom check existing files properly.
If it happens that a half downloaded torrent has to be removed and added again later, this bug also kicks in. I have one such d/l that have taken me 2 months to download only to 60%. I had to take it offline and start it again. It went back to 0% even as it was the same directory int use that "Bits on Wheels" correctly count to 60% downloaded. This is really really bad and is becoming a showstopper for me.

How is it possible that truly serious bugs like these that seem to affect many are left in for years and years? If it was a Java app I would try and fix this problem, but this is unfortunately not possible for me.