Corrupt SSD: Sorry, MobileMe, you were only a symptom
For the past week I've been plagued with random password errors on one of my Macs, the MacBook Pro 13in. First MobileMe started asking for the password which wasn't accepted because of a keychain error. I wrote about this here and here. I got help from the Apple Discussions forums and attempted to reset MobileMe. Several times I restored all the data on the MacBook Pro from the MM cloud, including the keychain which I suspected was at the root of the problem.
Then I started getting strange problems with other passwords. I couldn't log into my Google Reader account, despite verifying the details with 1Password and re-entering the password dozens of times. This happened with Instapaper and some other accounts at random. There seemed to be no sense in all this but I was convinced that the keychain was the culprit.
To be on the safe side, I decided to check disk permissions in Disk Utility, something I know I should do every week or so but continually forget to perform. This time there was a long list of inconsistences. There are always a few, but never this many. And repairing permissions solved some problems but left a long string of errors uncorrected. Time to verify the disk (which is a 256GB SSD fitted as original equipment by Apple). Not surprisingly, in view of what had gone before, the disk showed corruption and I was recommended to reinstall OS X.
I have now done this twice. The first time I reinstalled everything, using Migration Assistant, but after a few hours when I checked the disk it was again corrupt. I have had catastrophic HDD failures in the past but never something like this where the disk is corrupt but, in general, appears to function normally. I now suspect the SSD is faulty and I have a Genius Bar appointment tomorrow at the Regent Street Apple Store to look further into the matter. I'll be presenting them with a newly formatted computer with a fresh installation of OS X. I wonder if they will find anything wrong with the SSD?