screen flickers during cold boot

So I have a bit of a problem here. Recently, whenever I cold boot (shut down and tun on) my laptop, the screen flickers during the bot process. Most of the time it occurs from POST to when I get a usable desktop. Occasionally, it persists until up to a minute after startup. The flickering is not anything serious. By flicker, I mean that the screen displaces itself horizontally for a fraction of a second and the becomes normal again. This happens in about 4 second intervals. I'm using a T400 with windows 7 and intel graphics.

Here's what I diagnosed so far:
1) it's not a graphics driver problem since the problem still persists after I uninstalled the driver and even installed an older version of it

2) it only happens during a cold boot. the screen is okay when I do a restart

Has this happened to anyone else? I really hope this isn't a hardware problem since my warranty expired 3 months ago.

 

how are you setting up the ram? i.e. equal pair or unequal pair (i.e. 2 + 2 gig or 1+2 gig) or single stick?

 

the ram is 2+2gb and I have been using the same ram for over a year now.

 

try updating the bios and see whether that helps.

I can't make a determination as to whether this is a software issue or a hardware issue. Try connecting to the external LCD, and see whether this occurs.

 

I already have the latest BIOs and currently I don't have an LCD to connect to.
Also, an update. It seems that the shaking also happens when it resumes from sleep.

 

run a memtest on the laptop, also prime95 and see what happens. If you take the battery out and use only the ac adapter does this behaviour still occur?