I am running Bitcoin-Qt for Mac 0.8.1 beta
I received a "wallet.dat corrupt salvage failed" error and the client refused to launch.
I replaced the wallet.dat with a backup made a few hours earlier and on launching the client, I found that almost all my Bitcoins had been transferred to an alien address which I did not recognise, and had certainly not initiated.
One possible explanation is that these Bitcoins have been transferred to a Change address. But how can I access this?