Screen blanks for 3 seconds

[rokahn]

T400s running Windows XP
Every day or so since I bought it a month ago, the screen goes black for about 3seconds, then comes back. This happens with internal or external monitor. When used with external monitor, I'm also using an external keyboard/mouse so there's no physical manipulation of laptop that could cause, say, a connector to experience an intermittent break.

Anyone else experiencing this? It's not bad enough I want to deal with tech support (and since it's an intermittent issue, they're not equipped to deal with this anyway...they'd probably have me spend a day reinstalling the OS).

[rokahn]

I did a fresh install of Windows 7 (64) and still have the screen blanking behavior. I associate it with the OS asking if a program should be allowed to make changes to the system (before the dialog appears, the rest of the screen greys out...but first the screen blanks for 2-3 seconds). I installed system update and have the latest recommended drivers...any advice?