If you own a 2010 MacBook Pro with NVidia graphics, you may want to listen up if you plan to upgrade to Lion. Apple's Arrandale-equipped 15" and 17" MacBook Pros with switchable NVidia GT 330M graphics have been affected by a set of bad drivers. The NVidia graphics drivers that shipped with OS X 10.7 are causing kernel panics and system freezes that render the 2010 MacBook Pros unusable. Apple's support engineers are actively investigating the issue, according to Ars Technica. There are no easy solutions though, leaving most users no choice but to roll back to Snow Leopard.
However, for those who are like to do things by themselves, there are two solutions that may work. The first solution involves using the gfxCardStatus utility to disable NVidia graphics or disable sleep. AppleCare support technicians have offered a solution that may work as well. Navigate to ~/Library/Preferences/ByHost/ and delete all files containing "windowserver". To get to the Library on Lion, hold down the Option key in the Finder's Go menu, and use the Go to Folder command.
Symptoms of the problem include kernel panics, inability to wake from sleep, and black screens. Switching the NVidia graphics on and connecting a external display are some situations that cause problems. In addition, running games or graphics-intensive applications cause the problems as well. During beta testing of Lion, the issue was known but never fixed, leaving users frustrated with Apple.