[GM45] (Needs UXA) Kubuntu X server crash when screensaver is started (4500MHD with EXA)

Binary package hint: xserver-xorg-video-intel

My machine was idle and I suspect screensaver started, which caused crash of X server and I got back to KDM screen.
I was using EXA due to bug with UXA (which otherwise is much better) - see bug 347587

From /var/log/kdm.log:

error setting MTRR (base = 0xd0000000, size = 0x10000000, type = 1) Invalid argument (22)
 ddxSigGiveUp: Closing log

X.Org X Server 1.6.0
Release Date: 2009-2-25
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-15-server x86_64 Ubuntu
Current Operating System: Linux lure 2.6.28-11-generic #37-Ubuntu SMP Mon Mar 23 16:40:00 UTC 2009 x86_64
Build Date: 20 March 2009 02:02:41PM
xorg-server 2:1.6.0-0ubuntu4 (<email address hidden>)
 Before reporting problems, check http://wiki.x.org
 to make sure that you have the latest version.
Markers: [ 0.038652] (--) probed, [ 0.038667] (**) from config file, [ 0.038677] (==) default setting,
 [ 0.038687] (++) from command line, [ 0.038698] (!!) notice, [ 0.038708] (II) informational,
 [ 0.038717] (WW) warning, [ 0.038727] (EE) error, [ 0.038737] (NI) not implemented, [ 0.038748] (??) unknown.
[ 0.038809] (==) Log file: "/var/log/Xorg.0.log", Time: Wed Mar 25 13:15:20 2009
[ 0.106865] (==) Using default built-in configuration (48 lines)
[ 0.454960] (EE) open /dev/fb0: No such file or directory
exaCopyDirty: Pending damage region empty!

Backtrace:
0: /usr/bin/X(xorg_backtrace+0x26) [0x4f1996]
1: /usr/bin/X(xf86SigHandler+0x41) [0x485ab1]
2: /lib/libc.so.6 [0x7ff72f069040]
3: /usr/lib/libdrm_intel.so.1(drm_intel_bo_map+0x4) [0x7ff72d07e774]
4: /usr/lib/xorg/modules/drivers//intel_drv.so(i965_prepare_composite+0x1f1) [0x7ff72d2dc431]
5: /usr/lib/xorg/modules//libexa.so [0x7ff72c23bce2]
6: /usr/lib/xorg/modules//libexa.so(exaComposite+0x645) [0x7ff72c23c685]
7: /usr/bin/X [0x539de8]
8: /usr/bin/X [0x53245a]
9: /usr/bin/X(Dispatch+0x364) [0x44e354]
10: /usr/bin/X(main+0x3bd) [0x433ddd]
11: /lib/libc.so.6(__libc_start_main+0xe6) [0x7ff72f0545a6]
12: /usr/bin/X [0x433269]
Saw signal 11. Server aborting.
 ddxSigGiveUp: Closing log
 ddxSigGiveUp: re-raising 11

X.Org X Server 1.6.0
Release Date: 2009-2-25
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-15-server x86_64 Ubuntu
Current Operating System: Linux lure 2.6.28-11-generic #37-Ubuntu SMP Mon Mar 23 16:40:00 UTC 2009 x86_64
Build Date: 20 March 2009 02:02:41PM
xorg-server 2:1.6.0-0ubuntu4 (<email address hidden>)
 Before reporting problems, check http://wiki.x.org
 to make sure that you have the latest version.
Markers: [ 0.000707] (--) probed, [ 0.000720] (**) from config file, [ 0.000730] (==) default setting,
 [ 0.000739] (++) from command line, [ 0.000749] (!!) notice, [ 0.000758] (II) informational,
 [ 0.000767] (WW) warning, [ 0.000776] (EE) error, [ 0.000785] (NI) not implemented, [ 0.000794] (??) unknown.
[ 0.000855] (==) Log file: "/var/log/Xorg.0.log", Time: Wed Mar 25 14:06:49 2009
[ 0.044003] (==) Using default built-in configuration (48 lines)
[ 0.067284] (EE) open /dev/fb0: No such file or directory
exaCopyDirty: Pending damage region empty!

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 9.04
Package: xserver-xorg-video-intel 2:2.6.3-0ubuntu2
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersion: Linux version 2.6.28-11-generic (buildd@crested) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #37-Ubuntu SMP Mon Mar 23 16:40:00 UTC 2009
SourcePackage: xserver-xorg-video-intel
Uname: Linux 2.6.28-11-generic x86_64

[lspci]
00:00.0 Host bridge [0600]: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub [8086:2a40] (rev 07)
 Subsystem: Lenovo Device [17aa:20e0]
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07)
 Subsystem: Lenovo Device [17aa:20e4]