I did the update as soon as it came out and ever since my HP w2207 monitor will not come back to life after the mid 2011 21.5" i7 iMac wakes up. I have to go to system preferences, display and then click on arrangement and check the mirror box to make OSX see the display. I then uncheck the box and close the windows. I have to do this every time the screen goes to sleep. I know this is an update problem because people are reporting the same problem over on the apple.com forums. In my case everything was working perfectly until immediately after upgrading... Is anyone having a similar problem and any easy work arounds??