This happened to me today (again). Latest OSX, bitcoin-qt 0.8.5. FileVault 2 enabled, but it doesn't sound like that matters.
Any update/progress?
You can follow along here:
https://github.com/bitcoin/bitcoin/issues/2770It's being worked on, but hasn't been completely squashed yet.
this problem has gotten so bad with OSX that i've gone back to the Windows version.
I suggest running Mac client v0.7.2 (with the May 15 workaround) if you want to maintain a flawless OSX experience until things are sorted out.