Monitor Detection

[B Linky]

Hi,

I have a curious problem. Sometimes the Xserver will detect the
monitor (a Dell E17 LCD) and its supported resolutions, other times it
doesnt and switches to 800x600.. in which case, If the user logs out,
and hence the server restarts, then things are fine again.

I've uploaded the log files..
http://www.2shared.com/file/2810544/88e4625/Xlog-lowres.html    - for
where the monitor isnt detected and
http://www.2shared.com/file/2810572/cac0b0d3/Xlog-hires.html    -
where things are fine

Along with the xorg.conf file:
http://www.2shared.com/file/2810574/23a315e6/xorg.html

But the relevant lines seem to be:

(II) LoadModule: "ddc"(II) Module already built-in
(II) I810(0): VESA VBE DDC supported
(II) I810(0): VESA VBE DDC Level none
(II) I810(0): VESA VBE DDC transfer in appr. 0 sec.
(II) I810(0): VESA VBE DDC read failed
(II) I810(0): Will use BIOS call 0x5f05 to set refresh rates for CRTs.
(--) I810(0): Maximum space available for video modes: 12288 kByte

when its not working, compared with :

(II) I810(0): VESA VBE DDC supported
(II) I810(0): VESA VBE DDC Level 2
(II) I810(0): VESA VBE DDC transfer in appr. 1 sec.
(II) I810(0): VESA VBE DDC read successfully
(II) I810(0): Manufacturer: DEL  Model: a00a  Serial#: 876696652
(II) I810(0): Year: 2004  Week: 1
(II) I810(0): EDID Version: 1.3
(II) I810(0): Analog Display Input,  Input Voltage Level: 0.700/0.700 V
(II) I810(0): Sync:  Separate
(II) I810(0): Max H-Image Size [cm]: horiz.: 34  vert.: 27
(II) I810(0): Gamma: 2.20
(II) I810(0): DPMS capabilities: StandBy Suspend Off; RGB/Color Display
(II) I810(0): Default color space is primary color space
(II) I810(0): First detailed timing is preferred mode
(II) I810(0): redX: 0.640 redY: 0.340   greenX: 0.279 greenY: 0.619
(II) I810(0): blueX: 0.140 blueY: 0.069   whiteX: 0.310 whiteY: 0.330
(II) I810(0): Supported VESA Video Modes:
(II) I810(0): 720x400 at 70Hz
(II) I810(0): 640x480 at 60Hz
(II) I810(0): 640x480 at 75Hz
(II) I810(0): 800x600 at 60Hz
(II) I810(0): 800x600 at 75Hz
(II) I810(0): 1024x768 at 60Hz
(II) I810(0): 1024x768 at 75Hz
(II) I810(0): 1280x1024 at 75Hz

.. where it does work

Any thoughts/suggestions would be appreciated.