xrandr reports incorrect maximum screen size

Binary package hint: x11-xserver-utils

$ lsb_release -rd
Description: Ubuntu karmic (development branch)
Release: 9.10
$ apt-cache policy x11-xserver-utils
x11-xserver-utils:
  Installed: 7.4+2ubuntu3
  Candidate: 7.4+2ubuntu3
  Version table:
 *** 7.4+2ubuntu3 0
        500 http://us.archive.ubuntu.com karmic/main Packages
        100 /var/lib/dpkg/status

My expectation is that xrandr will recognize the correct maximum 3200x1200 size on my Thinkpad T400 laptop and will allow me to set the size to 3200x1200. My maximum screen resolution is 3200x1200, and I used this resolution on a dual external monitor setup when docked. I use xrandr to set up my screen resolution when docked with the following script that, until this morning, has worked just fine:

#! /bin/sh
xrandr --output LCD --off && \
xrandr --fb 3200x1200 \
       --output DFP1 --auto \
       --output CRT1 --auto --right-of DFP1

Within the past three days of updates to karmic (somewhere between 10/9/9 and 10/12/9), the script above stopped working, and the root cause of this is that the maximum screen resolution as seen by xrandr is only 2048x2048 instead of the required 3200x1200. The following is what xrandr returns when I attempt to set this size:

$ xrandr --fb 3200x1200
xrandr: screen cannot be larger than 2048x2048 (desired size 3200x1200)

ProblemType: Bug
Architecture: amd64
Date: Mon Oct 12 13:48:07 2009
DistroRelease: Ubuntu 9.10
MachineType: LENOVO 2767A15
NonfreeKernelModules: fglrx
Package: x11-xserver-utils 7.4+2ubuntu3
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcCmdLine: root=UUID=0db23939-f761-46f2-9285-220fb8cc6b9e ro acpi_osi="Linux" quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-13.44-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.6.0-1ubuntu2
 libdrm2 2.4.14-1ubuntu1
 xserver-xorg-video-intel 2:2.9.0-1ubuntu1
 xserver-xorg-video-ati 1:6.12.99+git20090825.fc74e119-0ubuntu3
SourcePackage: x11-xserver-utils
Uname: Linux 2.6.31-13-generic x86_64
dmi.bios.date: 01/09/2009
dmi.bios.vendor: LENOVO
dmi.bios.version: 7UET56WW (2.02 )
dmi.board.name: 2767A15
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7UET56WW(2.02):bd01/09/2009:svnLENOVO:pn2767A15:pvrThinkPadT400:rvnLENOVO:rn2767A15:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2767A15
dmi.product.version: ThinkPad T400
dmi.sys.vendor: LENOVO
system:
 distro: Ubuntu
 architecture: x86_64kernel: 2.6.31-13-generic