Parallels 8 Crawls with every VM I've got.

This iMac has a 3Ghz Core2Duo, 8GB ram, 256GB SSD with 76GB spare. WinXP, Vista 64, and 7 64 bit have all run fairly well on this machine using MacOS 10.6, 10.7, and 10.8 with Parallels 7. In fact these operating systems ran fairly well with earlier versions of Parallels - v5 and v6.

Now I'm getting 100% CPU usage with XP and the 64 bit OS's are running at 180%. These VM's have been working fine for several years. Where's the bug fix? My current version of Parallels is Build 8.0.18314 with Revision dated Oct 31, 2012

Currently, I'm trying to launch Windows 7 and I've been waiting for over 5 minutes for the first screens to come up. I've been watching Activity Monitor and both CPU cores are running at max.

This system is running slower than the old VirtualPC emulator and Win98. If this continues I'm going to have to reinstall P7 and revert to backup copies of my VM's. Is this really the only answer? That's going to take over a half a day cleaning out the new files, reinstalling the old Parallels and updating to v7, then restoring the VM's from backups. Does the uninstaller with v8 remove every trace of every version of Parallels from my machine?

Note: XP was running very high CPU with a service named mpsigstub.exe