On both our MBP as well as our iMac I can get OS X to crash when using a perfectly fine fragment shader, which works well under Linux. Both under Linux as well as under OS X I am using NVIDIA hardware. This is what the crash looks like:
Update 2010-07-13: Apple already wrote back, and requested a sample app, which I provided. Let’s see if they can figure this out. Kudos for reacting so quickly!