Earlier versions of VB would stall at 97% save state, now saving usually works, but in 50% of the cases I'm getting:
Failed to start the virtual machine XP-Workstation.
Unable to restore the virtual machine's saved state from '/media/NIXDATA/VM/Snapshots/{51957fcc-d5f6-4f4f-953c-a918122a934b}.sav'. It may be damaged or from an older version of VirtualBox. Please discard the saved state before starting the virtual machine (VERR_SSM_UNEXPECTED_DATA).
I'm using VB 2.2.4 on Ubuntu 9.04 64 bit. Discarding and restarting the VM works fine.