EM64T, Debian, i965: DRM_I830_CMDBUFFER: -22

[Andrew J. Barr]

I got back to my i965 machine after a few days, and now I remember why I
hadn't tried compositing managers there:

andrew at conroe:~$ glxgears
libGL warning: 3D driver claims to not support visual 0x5a
DRM_I830_CMDBUFFER: -22

andrew at conroe:~$ dmesg |tail -1
[drm:i915_cmdbuffer] *ERROR* i915_dispatch_cmdbuffer failed

andrew at conroe:~$ dpkg -s libgl1-mesa-dri
Package: libgl1-mesa-dri
Status: install ok installed
Priority: optional
Section: libs
Installed-Size: 30384
Maintainer: Mesa package maintainers
<pkg-mesa-devel at lists.alioth.debian.org>
Architecture: amd64
Source: mesa
Version: 6.5.1-0.4
Replaces: xlibmesa-dri (<< 1:7.0.0)
Depends: libc6 (>= 2.3.5-1), libdrm2, libexpat1 (>= 1.95.8),
libgl1-mesa-glx (= 6.5.1-0.4)
Conflicts: xlibmesa-dri (<< 1:7.0.0)
Description: A free implementation of the OpenGL API -- DRI modules
 This version of Mesa provides GLX and DRI capabilities: it is capable
of
 both direct and indirect rendering.  For direct rendering, it can use
DRI
 modules from the libgl1-mesa-dri package to accelerate drawing.
 .
 This package does not include the OpenGL library itself, only the DRI
 modules for accelerating direct rendering.
 .
 For a complete description of Mesa, please look at the
 libgl1-mesa-swx11 package.

andrew at conroe:~$ uname -a
Linux conroe 2.6.19-rc6 #3 SMP PREEMPT Sun Nov 19 10:32:15 EST 2006
x86_64 GNU/Linux

Any ideas on what's wrong here?

TIA,
Andrew