I've tried all torrent clients for Mac. For some reason if I leave them on, and go to work / bed, when I return they've frozen & don't even want to force quit. Can't be the torrent clients, I've tried all of them. The only way then to shut down my iMac is holding in the power button at the back. Can't be good for my Mac. The torrent client I currently use is Transmission & lastly I tried Bits on Wheels. Handbrake just quits after a while as well. I'm running Leopard 10.5.2, fully updated on an Intel iMac.