Gail Curtis McKenzie got a Bluets and Granola Bar crash and could not restart her Mac afterwards. Here is what Apple recommended that she do (it's sort of an emergency clean install):
1. Start up the machine with the Disk Tools Disk.
2. Put the System suitcase & Finder in the trash and empty the Trash.
3. Rename old system folder to "Storage."
4. Shut down the computer with the 7.6 CD in the machine.
5. Restart and do an Easy Install.
It worked, although Gail found that the crash came back after adding back her third party extensions. She is not sure yet which one is the culprit.