[Bug 44620] system crashes when the screen resolution is changed and dual head is enabled

[Douglas]

Public bug reported:

Ubuntu Dapper locks up when screen resolution is changed when dual head
mode is enabled. It will also lock up when the user logs out. This is
very close to bug #31516 which was fixed. Disabling dual head mode stops
the lock up. It works fine in breezy.

My graphics card is RV350 [Mobility Radeon 9600 M10] (ati)

To reproduce this bug one would need to
$sudo dpkg-reconfigure -phigh xserver-xorg
$sudo aticonfig  --initial=dual-head

Here's my lspci

$ lspci
0000:00:00.0 Host bridge: Intel Corporation 82855PM Processor to I/O Controller (rev 03)
0000:00:01.0 PCI bridge: Intel Corporation 82855PM Processor to AGP Controller (rev 03)
0000:00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01)
0000:00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01)
0000:00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01)
0000:00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 01)
0000:00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 81)
0000:00:1f.0 ISA bridge: Intel Corporation 82801DBM (ICH4-M) LPC Interface Bridge (rev 01)
0000:00:1f.1 IDE interface: Intel Corporation 82801DBM (ICH4-M) IDE Controller (rev 01)
0000:00:1f.5 Multimedia audio controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 01)
0000:01:00.0 VGA compatible controller: ATI Technologies Inc RV350 [Mobility Radeon 9600 M10]
0000:02:00.0 Ethernet controller: Broadcom Corporation BCM4401 100Base-T (rev 01)
0000:02:01.0 CardBus bridge: Texas Instruments PCI4510 PC card Cardbus Controller (rev 02)
0000:02:01.1 FireWire (IEEE 1394): Texas Instruments PCI4510 IEEE-1394 Controller
0000:02:03.0 Network controller: Intel Corporation PRO/Wireless 2200BG (rev 05)

** Affects: metacity (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

-- 
system crashes when the screen resolution is changed and dual head is enabled
https://launchpad.net/bugs/44620