nVidia GeForce 8500GT + Old Monitor = Low resolution

So I've just installed Ubuntu 11.10 on my old PC.
It has an nVidia 8500GT, and the Desktop monitor is pretty old though; like 1998 old. I have installed the drivers using this guide: how-to-install-nvidia-2750907-driver at mygeekopinions.blogspot.com

It's a CRT monitor. Philips 201b4. I guess that's the problem.

Could you help me get 1280by1024 or something? Thanks

xorg.conf

Section "Device"
    Identifier  "Default Device"
    Option  "NoLogo"    "True"
EndSection

xrandr -q

xrandr: Failed to get size of gamma for output default

Screen 0: minimum 320 x 240, current 640 x 480, maximum 640 x 480
default connected 640x480+0+0 0mm x 0mm
   640x480        50.0* 
   320x240        51.0