Lately I have been getting a blue screen whenever I logout in Leopard 10.5.8.
(And sometimes I have been getting a blue screen when I boot up. It never gets to the login screen).

I tried trashing the com.apple.loginwindow.plist in Library/Preferences but that did not fix it.
Also tried repairing the disk etc with Applejack. No luck..

I tracked down the problem to Tuxera NTFS. I believe the bug started with the 2011.4 version. But the problem still exists in the latest 2012.3 version.

I had to uninstall Tuxera to get the login screen to work again using the following steps:

Boot into safe mode (by holding down the SHIFT key at boot time after the chime).
Trash the com.apple.loginwindow.plist in Library/Preferences.
Uninstall Tuxera (using the UNISTALL button in the Preference pane)
Reboot.

Now the login screen works again.

It looks like others are also having problems with Tuxera under Leropard.
See http://forums.macrumors.com/showthread. ... st14679678

I hope the big gets fixed.

P.S. I am running an Intel Mac Pro tower.