I had a strange 'double' update experience from 10.8.0 to 10.8.1 on my mid-2009 13"MBP. I went to the software update section of the App Store, was notified of the 10.8.1 update, agreed, dowloaded the 40-something MB parcel, installed, and the computer restarted itself. Took around 20 minutes to install (at least, that's what was predicted; I wandered off and wasn't there when it finished). On logging into my user account again, I had no control over the volume. Sound was being output at a fairly normal volume, but I was unable to change the system volume. F10-F12 keys; menubar icon; System Preferences; Apple remote+mic in the headphone socket; all of these were tried and failed. The volume display square appeared grey (ok, greyer than normal) in the middle of the screen when I pressed the buttons, with no 'pips' representing the volume. The menubar control was greyed out and unmovable. The system preferences pane had the mute box ticked, but it was not changeable. Furthermore, Messages kept notifying me that there was a new message, but would not show it to me. I would go to the thread, the blue circle would disappear, then it would reappear a few seconds later. There was a message in the thread on my iPhone that would not appear in Messages on the Mac, for no reason I can think of. I checked About My Mac, and it said I was on 10.8. Not 10.8.1; just 10.8. So I went into the App Store again ... and there is another ML update. "What have I got to lose?" I said to myself. A 7.2MB download, two minutes of installation, and a restart later, my MBP finally seems convinced that it is running 10.8.1. The earlier problems with volume control and Messages are gone. The only remaining vestige of what happened earlier is that my clock has been changed to Los Angeles time, when I am on the East Coast. Anyone else have a similar experience? Any suggestions about the twilight zone my MacBook Pro inhabited for a few hours?