So it was written...Another key combination...ctrl+alt+'+', ctrl+alt+'-'. You can switch between resolution (forgot to write it in last post).
# Modeline "1600x1200" 192.00 1600 1648 1816 2064 1200 1202 1212 1263
It's 1600x1200 for my monitor, it won't work with yours. That's why I say it's hardware-specific. If you know someone with the same model as you have and that person runs X with the resolution you want, you can copy modelines. In other cases it may work, but only 'may'.
To have a chance for good modelines you need to make sure you have correct monitor parameters in /etc/X11/XF86Config(-4), section "Monitor".
You should see two lines below:
Check if 'xx's are the same as written in your monitor's manual (in technical data). If you change them, exit X and start them again, new modes will be generated and will be probably better.
There's a program that can tell you modelines basing on the parameters above, unfortunatelly I can't recall its name. Anyone?