Hello I was running Ubuntu 10.04 on a desktop Dell Optiplex GX620 with onboard graphics Intel 82945g (945G), and even then I had to use `xrandr` to add mode 1280x1024 and edit the files in `/etc/gdm`, but it worked.

Support for Ubuntu version 10.04 is at an end and I was always getting reminders of it, so I downloaded ubuntu-12.04-desktop-i386.iso burnt the cd and did a clean install of ubuntu 12.04 not a distribution update, now maximum resolution is only 1024x768. I have updated the kernel now to version 3.5.0-10; however, there is no `gdm` folder in `/etc`, there is no `xorg.conf` file in `/etc/X11` folder, and when I run `xrandr` I get the following:

```
jo@jo-Lin:~$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 480, current 1024 x 768, maximum 1024 x 768
default connected 1024x768+0+0 0mm x 0mm
   1024x768       61.0* 
   800x600        61.0  
   848x480         0.0  
   640x480        60.0   

```

When I run `cvt` I get this result:

```
jo@jo-Lin:~$ cvt 1280 1024
# 1280x1024 59.89 Hz (CVT 1.31M4) hsync: 63.67 kHz; pclk: 109.00 MHz
Modeline "1280x1024_60.00"  109.00  1280 1368 1496 1712  1024 1027 1034 1063 -hsync +vsync  

```

Then I tried `xrandr` again several times:

```
jo@jo-Lin:~$ xrandr --newmode "1280x1024_60.00"  109.00  1280 1368 1496 1712  1024 1027 1034 1063 -hsync +vsync
xrandr: Failed to get size of gamma for output default
jo@jo-Lin:~$ xrandr --addmode default 1280x1024_60.00
xrandr: Failed to get size of gamma for output default
jo@jo-Lin:~$ xrandr --output default --mode 1280x1024_60.00
xrandr: Failed to get size of gamma for output default
xrandr: screen cannot be larger than 1024x768 (desired size 1280x1024)
jo@jo-Lin:~$  

```