Also, have you gone to the ATI or nVidia site and ensured you have the latest drivers for your video card?
I am on a 1 month old macbook pro??? Do you still think I need to update it?
>still think I need to update
Yes... no computer company builds one at a time with the "then current" software drivers for all hardware
A "master tape" (or hard drive image) is made at some point in time, with Operating System and Device Driver software current as of THAT date
That production master is then copied on each computer's hard drive during assembly... which means the master may be several months out of date
So... you are using a macbook pro... what about the rest of the questions in the links I posted?
Macs are self-maintaining in this area. As long as your OSX Lion is up to date, it's not a driver issue.
When you say it shows a white screen, do you literally mean that the entire screen goes white! If so, I'd get your machine to the nearest Apple store for a tune-up.
Otherwise, please be more specific or, better, post a screen capture of what you're seeing.