Downloading same things for the second time

my computer had turned off and azureus had not been properly shut down. Now when i opened it half of my finished torrents are downloading again.  Any reason why?

have you moved them from the original directory?

or did u renamed the files?

something similar to that happened to me..some of my downloaded sets dont want to upload after i changed their location on the hard..and actually i never found a solution for it..tried downloading them again and saving them in the new location,thought maybe it would seed that way,but it doesnt,just downloads again

things like that can happen for many reasons. after a crash µtorrent's cache can get corrupted or lost, so the program (azureus does that as well) will think that nothing is complete and start them again. or your music-player can easily save something in ID-tags, or change them somehow to add it's info in them, so for the time being that torrent-client is running it will think that all files are 100% complete, because you don't do "force recheck" for no reason, but then after crash and restart client will go ahead and scan them all torrents and recheck them and show some incomplete or even not started, that would show you that files' hash-code-sums have changed, what happens when file changes, even just a little bit. things like that happened to me also. especially the power outtage sucks big time, twice my µtorrent did that force recheck on ALL files, and once about 400 of 700 seeded torrents disappeared from it (also cache corrupt case), once 90% of torrents disappeared, but it was around 300 seeded...