* Does it happen when you alt-tab during a game transition? (This is a known bug)
Mmm, IIRC, I was shuffling between a few windows (messenger) but I didn't minimize Osu!
* Does it happen consistantly on specific songs?
So far, it's happened quite a few on Driving Myself.
* Is there a gradual slowdown before it freezes fully?
Nope. After the song, I would press back to menu and then it just stays black. It seems to grab most or all of my processing power since everything starts to stop by then. I can't even bring my task manager up to force close Osu!
* When does the freeze occur?
Mostly after a song, when returning to menu. I've had it happen once when I just moused over a song though, but that was after spamming spectate on a friend so that must be it (song is Driving Myself again, xD)