MacBook Pro Grey Screen Flashes

Hi,
My MacBook Pro (2006 model) has started occasionally flashing a grey screen. This happens about once every two hours of continuous use, and is very brief (ie. length of one screen refresh). Any thoughts on what could this be? I think it's a hardware problem - no recent software or hardware updates though.

The computer is getting old, but still functions fine. Runs 10.7.2, 2.33 GHz Intel Core 2 Duo, 2GB memory.

Thanks!

I was working on my friends 2007 15" Macbook Pro and he was having a similar issue as well as a pixelated line running on the left side of the screen. I took it apart and reseated the lcd cables on the logicboard as well as on the back of the monitor. That seemed to do the trick and he no longer had either issue. It's only been about a week since I did it but he hasn't complained about it since. So I would try to do that if you can.

Wow! Thanks! Although that might be a little beyond my level of technical expertise, Haha.

Do you think it's an issue that's just focused on the display, eg. the LCD cables? The flashing is regular, but its not a permanent line through the screen. It could be a loose connection, or is it some other piece of hardware?