I can confirm compiz is causing the lockup. I installed compiz under the xubuntu jaunty live cd.
When I ran "compiz --replace" compiz gave the usual "Checking for ..." output, followed by the error:
/usr/bin/compiz: 455: /usr/local/bin/compiz: not found
exec: 455: /usr/bin/xfwm: not found
After which xubuntu kept running without problems
Then I ran "sudo compiz --replace" and the system locked up in exactly the same way as gnome and kde do: the desktop background is visible and the mouse can be moved around, but the system is locked.
Finally, after a reboot and mounting my hard drive, i tried to capture the output of "sudo compiz --replace > /mnt/sda3/out 2> /mnt/sda3/err". Of course, the live cd locked up, and when I rebooted from my hard disk I found the following from the standard output:
Checking for Xgl: not present.
xset q doesn't reveal the location of the log file. Using fallback /var/log/Xorg.0.log
Detected PCI ID for VGA:
Checking for texture_from_pixmap: not present.
Trying again with indirect rendering:
Checking for texture_from_pixmap: present.
Checking for non power of two support: present.
Checking for Composite extension: present.
Checking screen 1Comparing resolution (1280x800) to maximum 3D texture size (2048): Passed.
Checking for Software Rasterizer: Not present.
Checking for nVidia: not present.
Checking for FBConfig: present.
Checking for Xgl: not present.
Nothing had been saved from the error output, however.
Some additional info:
I can confirm compiz is causing the lockup. I installed compiz under the xubuntu jaunty live cd. bin/compiz: not found
When I ran "compiz --replace" compiz gave the usual "Checking for ..." output, followed by the error:
/usr/bin/compiz: 455: /usr/local/
exec: 455: /usr/bin/xfwm: not found
After which xubuntu kept running without problems
Then I ran "sudo compiz --replace" and the system locked up in exactly the same way as gnome and kde do: the desktop background is visible and the mouse can be moved around, but the system is locked.
Finally, after a reboot and mounting my hard drive, i tried to capture the output of "sudo compiz --replace > /mnt/sda3/out 2> /mnt/sda3/err". Of course, the live cd locked up, and when I rebooted from my hard disk I found the following from the standard output:
Checking for Xgl: not present. from_pixmap: not present. from_pixmap: present.
xset q doesn't reveal the location of the log file. Using fallback /var/log/Xorg.0.log
Detected PCI ID for VGA:
Checking for texture_
Trying again with indirect rendering:
Checking for texture_
Checking for non power of two support: present.
Checking for Composite extension: present.
Checking screen 1Comparing resolution (1280x800) to maximum 3D texture size (2048): Passed.
Checking for Software Rasterizer: Not present.
Checking for nVidia: not present.
Checking for FBConfig: present.
Checking for Xgl: not present.
Nothing had been saved from the error output, however.