Most times Xorg.log doesn't have a backtrace. I saved one with that did
have it, below:
[23.026]
X.Org X Server 1.10.2.902 (1.10.3 RC 2)
Release Date: 2011-07-01
[23.026] X Protocol Version 11, Revision 0
[23.026] Build Operating System: Linux 2.6.32-5-686-bigmem i686 Debian
[23.026] Current Operating System: Linux morsa 2.6.39-2-686-pae #1
SMP Tue Jul 5 03:48:49 UTC 2011 i686
[23.027] Kernel command line:
BOOT_IMAGE=/boot/vmlinuz-2.6.39-2-686-pae
root=UUID=b44364e8-9286-4a63-a555-4e68bba8f7cb ro quiet splash
acpi_osi=linux
[23.027] Build Date: 02 July 2011 10:49:30AM
[23.027] xorg-server 2:1.10.2.902-1 (Cyril Brulebois )
[23.027] Current version of pixman: 0.22.2
[23.027]Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[23.027] Markers: (--) probed, (**) from config file, (==) default
setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[23.027] (==) Log file: "/var/log/Xorg.0.log", Time: Thu Jul 21
09:52:54 2011
[23.068] (==) Using config file: "/etc/X11/xorg.conf"
[23.068] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[23.184] (==) No Layout section. Using the first Screen section.
[23.184] (**) |-->Screen "Default Screen" (0)
[23.184] (**) | |-->Monitor ""
[23.184] (**) | |-->Device "Intel Graphics Adapter"
[23.184] (==) No monitor specified for screen "Default Screen".
Using a default monitor configuration.
[23.184] (==) Automatically adding devices
[23.184] (==) Automatically enabling devices
[23.272] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not
exist.
[23.272]Entry deleted from font path.
[23.484] (==) FontPath set to:
/usr/share/fonts/X11/misc,
/usr/share/fonts/X11/100dpi/:unscaled,
/usr/share/fonts/X11/75dpi/:unscaled,
/usr/share/fonts/X11/Type1,
/usr/share/fonts/X11/100dpi,
/usr/share/fonts/X11/75dpi,
/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType,
built-ins
[23.484] (==) ModulePath set to "/usr/lib/xorg/modules"
[23.484] (**) Extension "Composite" is enabled
[23.484] (II) The server relies on udev to provide the list of input
devices.
If no devices become available, reconfigure udev or disable
AutoAddDevices.
[23.484] (II) Loader magic: 0x8232f20
[23.484] (II) Module ABI versions:
[23.484]X.Org ANSI C Emulation: 0.4
[23.484]X.Org Video Driver: 10.0
[23.484]X.Org XInput driver : 12.2
[23.484]X.Org Server Extension : 5.0
[23.485] (--) PCI:*(0:0:2:0) 8086:0116:1043:1712 rev 9, Mem @
0xdc40/4194304, 0xb000/268435456, I/O @ 0xe000/64
[23.485] (--) PCI: (0:1:0:0) 10de:0df6:1043:1712 rev 161, Mem @
0xdb00/16777216, 0xc000/268435456, 0xd000/33554432, I/O @
0xd000/128, BIOS @ 0x/524288
[23.485] (II) Open ACPI successful (/var/run/acpid.socket)
[23.485] (II) LoadModule: "extmod"
[23.505] (II) Loading /usr/lib/xorg/modules/extensions/libextmod.so
[23.525] (II) Module extmod: vendor="X.Org Foundation"
[23.525]compiled for 1.10.2.902, module version = 1.0.0
[23.525]Module class: X.Org Server Extension
[23.525]ABI class: X.Org Server Extension, version 5.0
[23.525] (II) Loading extension SELinux
[23.525] (II) Loading extension MIT-SCREEN-SAVER
[23.525] (II) Loading extension XFree86-VidModeExtension
[23.525] (II) Loading extension XFree86-DGA
[23.525] (II) Loading extension DPMS
[23.525] (II) Loading extension XVideo
[23.525] (II) Loading extension XVideo-MotionCompensation
[23.525] (II) Loading extension X-Resource
[23.525] (II) LoadModule: "dbe"
[23.525] (II) Loading /usr/lib/xorg/modules/extensions/libdbe.so
[23.540] (II) Module dbe: vendor="X.Org Foundation"
[23.540]compiled for 1.10.2.902, module version = 1.0.0
[23.540]Module class: X.Org Server Extension
[23.540]ABI class: X.Org Server Extension, version 5.0
[23.540] (II) Loading extension DOUBLE-BUFFER
[23.540] (II) LoadModule: "glx"
[23.540] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[23.556] (II) Module glx: vendor="X.Org Foundation"
[23.556]compiled for 1.10.2.902, module version = 1.0.0
[23.556]ABI class: X.Org Server Extension, version 5.0
[23.556] (==) AIGLX enabled
[23.556] (II) Loading extension GLX
[23.556] (II) LoadModule: "record"
[23.556] (II) Loading /usr/lib/xorg/modules/extensions/librecord.so
[23.620] (II) Module record: vendor="X.Org Foundation"
[23.620]compiled for 1.10.2.902, module version = 1.13.0
[23.620]Module class: X.Org Server Extension
[23.620]ABI class: X.Org Server Extension, version 5.0
[23.620] (II) Loading extension RECORD
[23.620] (II) LoadM
