I recently started having this issue a couple of weeks ago, had my macbook pro sent into apple, and repaired with a new logic board, keyboard, trackpad, and top case. My initial thought was that the video card needed replacing (I have the infamous 8600M GT). I've had my computer back for only a week and had the issue again: screen goes white with vertical pastel colored lines and then totally white. I also noticed that putting my computer to sleep and waking it will fix the problem. Could it be that I need my screen replaced?? It's now been in once for a new superdrive and again last week for the repair I mentioned above. I'm getting increasingly frustrated with this computer when it's not even 1.5years old! 
Thoughts, anyone? Thanks!!
This is what my screen looks like when it occurs: http://tweetphoto.com/5466154
EDIT: Do you think this would warrant a call asking (nicely) for a replacement MBP? I've now had 4 parts replaced in this computer, granted its only been in twice now..
Thoughts, anyone? Thanks!!This is what my screen looks like when it occurs: http://tweetphoto.com/5466154
EDIT: Do you think this would warrant a call asking (nicely) for a replacement MBP? I've now had 4 parts replaced in this computer, granted its only been in twice now..