XPS M1330 unsual display issue (Intel graphics)

Hello! I've searched everywhere and found nothing even remotely similar to what's happening to my lappy.
A while ago, I replaced my original -broken- MB (nVidia) for new one with the Intel integrated graphics so that I wouldn't have to deal with faulty display issues anymore. I'm glad to say I can now use my laptop except for a somewhat minor annoyance: when I cold-boot it (that is, after having it turned off for more than 2 minutes) I get no BIOS screen, no Windows startup screen but, after I while I get the Windows login but the screen shows only a 4:3 image to the left and a black stripe (to complete the 16:10 frame) to the right. The computer works fine, but with a smaller-than-usual display.
If I let the computer warm-up and power-cycle it, I get a fully functional PC again: BIOS screen, Windows startup and a bright 16:10 display which stays that way after sleeping and even after hibernating!

If I had to guess, I'd say the lappy's monitor isn't giving the right information when booted cold but it's giving it right afterwards. Is this even possible?

I'd gladly provide more details and even run more tests to anyone willing to help me out.

Thanks!

 

Have you gone to Intel's site to install the driver for the integrated graphic card?

 

I think I did that a while ago when I swapped MBs. I will give it a try this night, though. However, if it were a Windows driver problem it wouldn't explain why I get no POST screen while booting, would it? :S
Thanks!

 

Maybe try updating your BIOS (or downgrading it) to a different version. This may reset a critical value that is causing this issue?

 

Did that last night but nothing changed

The new MB came with an old BIOS, maybe A09 (I'm not sure). I really don't remember if this happened with that BIOS version but I'm guessing it didn't or I'd remember it, otherwise. I now have version A15 (the last one, to the best of my knowledge).
I'll try downgrading. Should I try any particular version or anyone will do? Is there any version I should absolutely not downgrade to?

Again, thank you both for your help

 

Try A14 first, see if that works. I wouldn't go any further back than about A12 (better thermal management implemented w/ A12).

Here's the link for M1330 BIOS versions, from Dell:

ftp://ftp.dell.com/bios/

 

I didn't find the time to do it last night. Will do it over the weekend and let you know. Thanks for the update!

 

So, I finally downgraded the BIOS but nothing changed. I also updated it back to A15, just in case
Could it be hardware related? Maybe the flex was damaged during MB-swap (?).