X.org / deal head problem

[<gavin.carey@thomson.com>]

System: Dell Optiplex GX270 with an additional old ATI Rage PCI video
card.
X-Window System Version 6.9.0 (21 dec 05)
Relevant(?) xorg.conf sections pasted at end..

Hi Folks,

For the past 18 months or so I've been happily running a Debian/GNU
"testing" install on this box, in a dual-head configuration, running a
15" tft off the ATI card and a 17" tft off the onboard video, everything
was great.

I hadn't run a "dist-upgrade" for some time, but one afternoon, with
some spare time, decided to do so.  It completed, and everything was
fine... until I rebooted.

At which point, only the 17" screen on the onboard video hardware fired
up and worked in X.

I've spent a few hours playing with "xorg.conf" files, and have
discovered the following:

When BIOS is set to "Auto", then the ATI card & 15" screen will work
(BIOS info appears here, as does my linux console, and assuming the
xorg.conf file is right, my X display goes here too).

When BIOS is set to "OnBoard", then the OnBoard card and 17" screen will
work (BIOS info appears here, as does my linux console, and assuming the
xorg.conf file is right, my X display goes here too).

[Prior to the issue materialising, BIOS was set to "OnBoard"]

When my xorg.conf is configured for dual-head, with the i810 side
working, the Xorg.0.log file shows:

(EE) ATI(1): Cannot read V_BIOS
(EE) ATI(1): Adapter has not been initialised.

[When using Option "NoINT10" in the ATI device section my "xorg.conf"
file the first line does not appear, but the 2nd does]

When my xorg.conf is configured for dual-head, with the ATI side
working, the Xorg.0.log file shows:

(EE) I810(0): VBE initialization failed.

On odd occasions, I have also seen "Cannot read V_BIOS" for the failing
i810, and additionally one lengthy error message listing that AGP was
not available.


During the dist-upgrade, I moved from Kernel 2.6.12 to 2.6.15, though
when booting with the old Kernel, I still have the same issue and error
messages.  I'm on the default Debian i686 kernel.



I've pretty much exhausted the sum total of my knowledge, so any help
which you might be able to offer would be greatly appreciated.

Regards,

Gavin.

Relevant xorg.conf sections:

Section "ServerLayout"
        Identifier     "DualHead"
        Screen         "Screen17"
        Screen         "Screen15" RightOf "Screen17"
        InputDevice    "Generic Keyboard"
        InputDevice    "Configured Mouse"
EndSection

Section "Monitor"
        Identifier   "Dell17"
 ### Comment all HorizSync and VertSync values to use DDC:
        HorizSync    31.0 - 80.0
        VertRefresh  56.0 - 76.0
        Option      "DPMS"
EndSection

Section "Monitor"
        Identifier   "Dell15"
 ### Comment all HorizSync and VertSync values to use DDC:
        HorizSync    32.0 - 59.0
        VertRefresh  57.0 - 74.0
        Option      "DPMS"
EndSection

Section "Device"
        Identifier  "IntelOnboard"
        Driver      "i810"
        BusID       "PCI:0:2:0"
EndSection

Section "Device"
        Identifier  "ATIRage"
        Driver      "ati"
        BusID       "PCI:1:7:0"
#        Option      "noINT10"   "yes"
EndSection

Section "Screen"
        Identifier "Screen15"
        Device     "ATIRage"
        Monitor    "Dell15"
        DefaultDepth     24
        SubSection "Display"
                Depth     24
                Modes    "1024x768"
        EndSubSection
EndSection

Section "Screen"
        Identifier "Screen17"
        Device     "IntelOnboard"
        Monitor    "Dell17"
        DefaultDepth     24
        SubSection "Display"
                Depth     24
                Modes    "1280x1024"
        EndS