hey hotplug..
i am not sure if it is hardware or not.. i also had this on 4 machines (all 9c84 screesn) everytime i called up apple they just said ok, sorry, we send a new unit..
but it kept coming back with the same problem.. 😟
i was hoping with the new 2.66 and 2.96 this might be solved, but you are proof it isnt, it is really frustrating, i do music production and stare on the screen for many hours and i get headaches (the software i use has a greyish background which makes the flicker quite visible)
i m not sure what to do, whether return the machine alltogether and take it from there (back to windows.. arghh.. dont wanna do that)
i have done some research, and i come up with different articles saying that nvidia are the ones to blame for the problem.. check out this article:
http://www.theinquirer.net/inquirer/news/670/1049670/nvidia-heat-causing-macbook s-to-fail
http://support.apple.com/kb/TS2377
cheers