I've got a VM running 10.6 Server on Fusion 4.1.0. The AutoProtect snapshot mechanism runs every night at 10pm. And every night at 10pm, as the snapshot runs, the VM slows to a crawl and then becomes unresponsive and I have to bounce it. If I turn the snapshots off, it's fine. The VM is encrypted and has an external USB drive mounted to handle Time Machine backups, but is otherwise unremarkable.
Any suggestions?