Thank you for your offer. I now did a clean install of Mountain Lion and just migrated my user data. However, I believe that something is not OK on Apple side regarding these problems. And some questions arise:
- Did you reset the Parameter-RAM (Cmd-Option-P-R during startup)?
- Is your partition encrypted?
The reason I ask this is that it took me quite some effort to reinstall a freshly new system. I alwas received a message telling me "A problem occured during installation. Try new" without any indication where the "problem" should be. I tried to start from various startup disks, I reformatted the drive entirely with no result. Only the reset of the Parameter RAM finally let me install Mountain Lion.
However, I still do not see a proper Security Pane (General). "Disable auto login" is still missing (a tribute to the encrypted disk?) and the check box is missing for the "Require password" bit and it looks kind of distorted.
But generally speaking it now works properly at least although I am not really convinced that ML is mature for release. They should have waited for a vetsion what we will receive as 10.8.2.