Not exactly a bug as such, but in the last week I've noticed that if I leave my iMac idle for anything more 25-30 minutes, when I come back the whole Unity/PM program has become unresponsive. Clicking anywhere in the windows then brings up the spinning wheel and I have to force quit it.
Running Unity without PM is fine, only when PM is left idle does this happen.
Anyone else seen this or have any ideas?