Hi ApoIce, if sax2 doesn't help you. You can change the settings in xorg.conf manually, as you have done it before.
For your monitor, you need three key specifications:
Reviewing the Monitor Section, I believe you should review the display size and the Vertical frequency.
About your graphic card, which one you have?, post the result of this command (run it as root):
In case you have a Nvidia card, you need to install the propietary driver. Meanwhile you can use the "vesa" generic driver as RanDrake10 pointed out.