This is odd because the update doesn't actually make any changes to the files themselves. Have you tried reverting to the previous version? I doubt this would make any difference though. Does anyone else have access to the files? That's something I would consider if you're absolutely certain you made no changes yourself.
Have you tried restarting your computer after the update?
There is a known problem with Keychain that is restored after a restart.
Hope this helps.
Doug, I agree a restart is necessary. However, if the OP is using the default ADMIN account and has never entered a password this might be a different issue.