Comment 2 for bug 938406

I'm running Ubuntu 12.04 x64, kernel 3.2.0-24-generic with an NVidia GTX460 and an Achieva Shimian QH270-Lite 2560 x 1440 monitor connected by a dual-link DVI cable.

I've installed the nvidia-current 313-09 drivers from xorg-edgers (and tried the 310-19 from NVidia). Neither of these drivers read the EDID information from my monitor (/var/log/Xorg.0.log) and default to lower resolutions which my monitor will not display, resulting in a black screen.

If I replace the high-res monitor with a lower resolution 1600 x 900 monitor it works fine.

I want to force my video card to the resolution I need. NVidia's Xserver settings doesn't change anything. The xorg.conf configuration file is deprecated and the file is untouched by 12.04 - that is to say it doesn't access it - so I tried xrandr.

First I queried xrandr for a modeline for my resolution:
john@Vivid01:~$ cvt 2560 1440 60
# 2560x1440 59.96 Hz (CVT 3.69M9) hsync: 89.52 kHz; pclk: 312.25 MHz
Modeline "2560x1440_60.00" 312.25 2560 2752 3024 3488 1440 1443 1448 1493 -hsync +vsync

Then set up a new mode for it:
john@Vivid01:~$ xrandr --newmode "2560x1600_60.00" 348.50 2560 2760 3032 3504 1600 1603 1609 1658 -hsync +vsync

And attempted to attach it to a display:
john@Vivid01:~$ xrandr --addmode DVI-I-1 "2560x1440_60.00"
X Error of failed request: BadMatch (invalid parameter attributes)
  Major opcode of failed request: 153 (RANDR)
  Minor opcode of failed request: 18 (RRAddOutputMode)
  Serial number of failed request: 31
  Current serial number in output stream: 32

It appears xrandr won't accept the custom resolution.