Ok I just upgraded to version 5 (specifically I'm running Build 5.0.9344). I converted over my virtual machines, and spent a couple days installing new software. I came in to work today, fired up the virtual machine on parallels and got the following message: The virtual machine cannot be used because its files are corrupted. And my options are to either delete the files or cancel. Is that really the answer here? If I have no options other than to delete the virtual machine, I'm seriously going to consider using VMWare.