Very weird computer start up problem ( resolutions )

Hi there

I got this very weird problem... (almost) every time I boot up my PC, it has a rather weird resolution...

Sometimes it gets into Windows with 800x600, other times it gets into 1680x1050 .. in panning mode.. While my screen supports 1680x1050! Other times it starts up at 1440x900.

If I want it to be in the good resolution, sometimes I can just select the good resolution on the ATI control screen. But sometimes, like on the panning mode I have to : Force rotate 180* , then force it back to 0*.. then it's on the good 1680 resolution again, without panning.

I got a PEAK HD4850 on a Samsung 2032MW ... trough the card's first DVI slot to a DVI-VGA converter to the VGA connection on the screen.

Can anyone tell me what's going on here?

[edit]

Also, when I am in a fullscreen application, wich is running on 1680, and I Alt-Tab out of it, the desktop resumes to the 1680x1050 in panning mode ( the screen itself is running on 1440x1050 then, and you when you move your mouse to the edge of the screen it moves )

Have you tried another video card? - Yes, my 7600GT, doesn't have these strange probs

Have you tried another monitor? - No

Do you have the latest drivers from ATI website? - Unless they've updated them in the last 14 days or so, yes.

Have you tried using the 2nd dvi port? - Yes, no difference


Thanks for the reply anyways

I am 100% sure I removed all old drivers, used Driver Sweeper from Guru3d, while in Safe Mode.

But I'll try this anyways, Thanks. It's getting really annoying.

[update]

And, some time later, I tried it all.
But alas, after I reinstalled the drivers and rebooted it went back to a panning mode.
Weirdly enough - This isn't happening on my Windows 7 Beta installation, on another partition.

I really don't know whats' going on here...