[SOLVED]After crash and reisntall resolution too small for..

I've got an absolutely bizarre problem with my laptop. A while ago I had a heavy system crash which stopped me using the latest kernel (it would only boot into the older one). Today I had another less heavy crash, in that I was at least able to CTL ALT Backspace and relog. However, since the reboot, the screen seems to have gone to something like a 800x600 window within the full resolution of the monitor (it's a 1920 x 1200). As I move the mouse around the screen and the mouse hits the edge of the screen, the screen moves so that the low res section of the screen moves to show the full extent of the screen resolution.
I have tried the following:
Delete the nvidia driver, use nouveau, reinstall nvidia driver. No help.
Delete xorg.conf and reconfigure. No help.
Reinstall Mageia completely. No help.
Delete .kde4 directory. No help.
Does this seem familiar to anyone? Have I explained it OK? Can anyone suggest what might be going on?
Thanks.
I have tried the following:
Delete the nvidia driver, use nouveau, reinstall nvidia driver. No help.
Delete xorg.conf and reconfigure. No help.
Reinstall Mageia completely. No help.
Delete .kde4 directory. No help.
Does this seem familiar to anyone? Have I explained it OK? Can anyone suggest what might be going on?
Thanks.