The message "One or more kernel components loaded on your Mac are for another version of Parallels Desktop" is interesting.
Have you used an earlier version of Parallels before on the computer?
Try uninstalling Parallels again. Then restart. Then go into Terminal.app and run the following command to list any running Parallels kernel extensions that are loaded:
kextstat | grep parallels
Parallels installs the following kexts:
Make sure they don't exist after you uninstall.
Parallels 4, 5, 6:
Run Activity Monitor, show all processes, and make sure you don't see any process names that start with prl_
Make sure you're not running an old Parallels Desktop app after installing a new Parallels Desktop app (which might happen if you have more than one partition with Mac OS X installed). If you're running it from the Dock then select Show in Finder. If you're running it from an alias, then right click and select Show Original. Then Get Info.