My guess is that some of the images for 6.5.22 did not get copied over correctly.
here is what I would do:
1. boot the box to a previous image
2. delete 6.5.22 altogerther
3. after that, shutdown the box, shut it off, then restart in order to run the diskcheck called "fsck"
4. The reboot will take longer since you are running fsck.. you should attach a console cable and watch
it run and see what the results are.. this is just in case some bad parts on the disk and this will clean them up.
If fsck does not run, after the box reboots, you can run it by typing nbxFsCheck... but it does shut down
the system entirely while it runs.
4. reload 6.5.22