I will share my 4 week adventure with lion and my new iMac..
I am a new mac user, and purchased a iMac 27" 1T 1GB GPU system.
Worked flawlessly with my aftermarket OWC 16GB RAM kit in SL.
Upgraded to lion and had a number of issues with the OS interface and video display.
- Funky patterns on the finder and desktop - greyed out interlaced icons / thumbnails
- Video from 5Dmkii (h.264) would play with filickering pink horizontal bars
- Kernal Panics
- Compressor taking a very very long time ot render video files
- Black screen with rainbow wheel after wakeup
I had my system recalled for the "seagate 1T HD issue" and replaced. Still the same issues.
I had my system bench tested by apple and Beyond the box (aurthorised repairer) and the hardware checked out fine.
I could replicate the issue always, videos would always flicker green / pink.
Apple icon on the top left bar would grey out once clicked.
Finder windows become greyed out momentarily when moved from one display to the other.
I when through the chain of apple care reps right through to senior staff, no fixes thus far.
I have had my machine replaced twice. And aftermarket RAM replaced twice.
I put the stock 8GB apple ram back in my system and that improved my video and graphical issues by 80%
Then I replaced my Aftermarket OWC RAM with OWC "Samsung Chips", and that is on par with my stock apple RAM - in terms of experienced issues.
Updated Lion many times including a squeaky clean manual install and that made no difference.
It seems the only improvements I could gain was to run SL or Lion 10.7.1 with stock RAM and OWC Samsung chip (part: OWC1333SAM3S4GB x 4)
I still have issues right now, but they are less occouring.
I do however get the awake issue from sleep mode still.
Im exhausted!