I have a really weird problem with my laptop. It's an ASUS K53S with nvidia geforce GT540M and optimus technology, which I'm not using at all. I should be using just the intel graphics card. When I connect my external monitor (Samsung 2033HD), at the best resolution (1600x900) I have problems with it. It's shaking, like it had some refresh rate problems, but the point is when I connect the same laptop to a different monitor (Samsung 24 inch) it works properly at 1920x1080. Furthermore, when I connect my netbook (ASUS 1215P with Intel graphic card) to the same monitor which has problems, everything works at 1600x900.
The actual refresh rate is 60 Hz and I cannot change it through xrandr. The xrandr output is the following:
Screen 0: minimum 320 x 200, current 2966 x 900, maximum 8192 x 8192
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
800x600 60.3 56.2
VGA1 connected 1600x900+1366+0 (normal left inverted right x axis y axis) 443mm x 249mm
1280x800 74.9 59.8
1024x768 75.1 70.1 60.0
800x600 72.2 75.0 60.3 56.2
640x480 72.8 75.0 66.7 60.0
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
One more attempt I tried: if I boot from the Ubuntu live distribution , the external monitor works like a charm, while I have the same problem with Fuduntu, which is based on Fedora.
What's the problem? Do you have any idea how to solve it?