Virtualbox 3.0.8 and 3.0.10, host OS Windows Vista
After upgrade problems in guest OS (Ubuntu 9.10) I tried to revert to a previusly saved snapshot.
When starting the restored machine state the virtual machine hangs showing a Critical Error message.
Snapshots were saved at 2009-09, after that I've installed Virtualbox updates and now tried to start saved snapsot with Virtualbox 3.0.8 and 3.0.10.
(For some reason you have to delete the current state before using previously saved states, so there's no way back as it seems)
I tried to attach the vbox.log file also, but it is 207 KB and exceeds the upload limit in the forum.