Identical problem here!
Two differences in my specs:
- Graphics AMD Radeon HD 6970M 1024 MB
- Use only iMac's display
Just to add one more problem (yes, I have the others below too): sometimes happen intense flicker in all display (not just window).
I suspect heat is cause of this annoying and worst if play game… If you use iStat Menus 3 can notice that. I hope a new driver fix it!
Sorry my grammar… English not is my natural language, but I'm sure you'll understand me. ;)
Thanks,
-
Specs:
27-in, Mid 2011 iMac
Processor 3.4 GHz Intel Core i7
Memory 12 GB 1333 MHz DDR3
Graphics AMD Radeon HD 6970M 2048 MB
Software Mac OS X Lion 10.7.1 (11B26)
Flash: version 10.3.183.10 installed
Java: java version "1.6.0_26"
Java(TM) SE Runtime Environment
Java HotSpot(TM) 64-Bit Server VM
Main problems:
1. Hangs on grey screen on reboot for 30s-5m. (...with these specs it should be around 20 seconds?)
2. Graphics artifacting on the usually mentioned places
3. Vertical lines through the iMac screen. (not other monitors, disappear on reboot)
4. None of the mid 2011 iMac Firmware updates are for my machine? ....
5. Some of the pink and green youtube flickering previously described. (log out/in works!)
6. Thunderbolt monitors lose desktop picture. (resetting image and logging out/in don't work, must reboot)
Logging out and back in does not work for me.
Also, I have 2 monitors connected over thunderbolt. Occasionally the background images for the other monitors disappears, changing the image doesn't reset it.
Windows still look fine on the other monitors, just have to restart to fix the vertical lines, youtube flicker, artifacting, desktop pictures temporarily.
Note: "JUST HAVE TO REBOOT"
It takes 5 minutes for my computer to reboot sometimes, there is no "just reboot and it goes away"