Is the GPU failing on my macbook?

Sometimes after I watch a video there will be a bunch of red pixels stuck all over the screen. Then usually the mac will freeze, although I am still able to move the mouse pointer around on the screen but clicking things does nothing. I have to hold the power button down to restart the mac. When I restart it everything works fine again... until I watch any type of video. Does this sound like a GPU problem? I do have Geforce 8600m and I heard of them failing in macbooks. If so then it is a bummer since the whole logic board will need replacement.

Yes, it is of the very likelyhood that the GPU is failing. If the Mac doesn't respond but the cursor moves, and red pixels are on the screen, the GPU is going bad.