Maximum resolution collapses from 1920x1080 to 640x480 on reboot

[Vassili Zaitsev]

Hi,

I was wondering whether anyone had ever experienced anything like this:--

A couple of days ago I was happily running Fedora 12, only to find that
on booting into it that the available screen resolution of 1920x1080,
which had been correctly detected on installation and maintained ever
since, had suddenly dropped to 640x480!

Assuming (incorrectly) that it was down to Fedora's policy of pushing
the nouveau driver and bleeding-edge X.org servers I moved the hidden
config files & directories over to an archive folder and proceeded to
install Ubuntu 9.10. The maximum resolution was also 640x480 -- strange,
as on the two other occasions I'd installed 9.10 it had been set correctly.

I also installed openSUSE 11.2, but again the maximum res was 640x480. I
then reinstalled Ubuntu 9.10, but this time followed the Ubuntu Wiki
instructions (https://wiki.ubuntu.com/X/Config/Resolution):

rm ~/.config/monitors.xml
xrandr [which correctly reported the maximum available resolution as
1920x1080]
xrandr --addmode default 1920x1080
xrandr --output default --mode 1920x1080 --rate 60 [subsequently added
to the GDM startup script]

Everything worked fine, until today when I booted into Ubuntu to find
that the resolution had collapsed. cvt indicates that it's possible to
add 1920x1080 to the list, but when I insert its modeline into "xrandr
--newmode" it returns an error:

$ cvt 1920 1080
# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088
1120 -hsync +vsync
$ xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080
1083 1088 1120 -hsync +vsync
X Error of failed request:  BadName (named color or font does not exist)
  Major opcode of failed request:  153 (RANDR)
  Minor opcode of failed request:  16 (RRCreateMode)
  Serial number of failed request:  18
  Current serial number in output stream:  18

The weird thing is that this doesn't seem to affect Windows XP at all;
if the monitor (an Acer X223HQ) had been reporting spurious EDID data or
the graphics card (an nVIDIA GeForce FX 5500) was playing up, presumably
I'd be encountering the same problems there.

Regards,

Vassili