MacBook Pro (6,2 - Mid 2010) Crashes During Graphics Acceleration
It sounds like a problem happening when the computer switches to the high-performance (discrete) chip–something in that transition is failing. Open Console from the Utilities folder, and find kernel.log.  See if there are any interesting lines at the time the crash happens.  Probably a few lines with "NVDA" in them.

If you open System Preferences and then Energy Saver, you can adjust the graphics mode - try setting it to high-performance (discrete) all the time.  Either the system will freeze right then, or you can attempt the same tests.  If you still see trouble, it's time to talk to Apple.