Snow Leopard Crashing

Hi -

I receive a random crash once in a while that I never received before installing Snow Leopard. A transparent gray wash falls over the screen and a black box pops up that simply says (in many different languages) that, "You must restart your computer. Hold down the power button on the back of the machine for two seconds."

Has anyone experienced this?

sounds like you've got a kernel panic, basically unix is having a breakdown. it usually occurs due to a hardware glitch.
if restarting doesn't solve the problem detach everything thats not mac.restore everything one at a time until you find out which one is causing probs with mac osx .
the only other thing i can think of is that you've moved or renamed files or changed permissions for mac osx's essential system files.
this has been happening to alot of people and could be a problem with drivers or firmware within sl.
you could try a safe boot up as this switches of all kernell extensions.there is a numerous amount of causes from corrupt fonts to non apple extensions,but if it's only happening since sl try a clean instal.