For the past days, I've seen a number of glitches on OS X Lion (update 10.7.3) with my mid-2010 Macbook Pro, and apparently, I'm not the only one.
It seems to happen especially on external monitors:
https://discussions.apple.com/message/17524501#17524501
However, iMacs have a lot more trouble:
https://discussions.apple.com/thread/3201871
A possible solution for the graphics glitches is mentioned at the end of the thread:
https://discussions.apple.com/message/17804906#17804906
UPDATE: this issue seems fixed with the 10.7.4 update
I've encountered a bug where the screen would blank, reproducible as follows:
I've also encountered a bug where the laptop screen would just stay black, not reproducible. I took the following steps:
Remotely I could log into the laptop, though.
Another set of circumstances happens as follows:
The following lines are then visible in the kernel.log:
--- last message repeated 1 time --- kernel[0]: NVDA(OpenGL): Channel timeout! --- last message repeated 1 time --- kernel[0]: NVDA(OpenGL): Channel timeout! --- last message repeated 1 time --- kernel[0]: NVDA(OpenGL): Channel exception! exception type = 0xd = GR: SW Notify Error kernel[0]: NVDA(OpenGL): Channel timeout! kernel[0]: NVDA(OpenGL): Channel exception! exception type = 0xd = GR: SW Notify Error kernel[0]: NVDA(DisplayBase): Channel timeout!
UPDATE: this is still occurring with 10.7.4 update. Workaround is to keep the lid open