Half my downloads just disappeared!!!

[saywhat]

I had about 250 downloads (active, completed, paused and stalled) and when I looked, after not paying attention to qBittorrent for a while, I noticed that half the downloads in my "ALL" list had disappeared so I now have only 127! I have found the files for a few I can remember being in the list but is there a way to easily recover all the ones that when AWOL?

Also any idea why this might have happened?

EDIT: I realise what happened. My drive space was critically low and qbittorrent started giving errors so I ran the disc cleanup routine for Windows 7 which must have deleted half of my torrents (no idea how though). The downloaded files are still there but is there a way to reassociate them to qbittorrent so I can complete the downloads?

2nd edit: IT's ok I figured out what to do. I searched for all .torrent extensions and will have to double click on each one to open it in qBittorrent. Pain in the rear but only way to do it as far as I can tell.