[nvidia]Blank screen after switching users

[debianmigrant]

Running Gusty Gibbon - i386 - Restricted NVidia drivers - Compiz enabled

Using user switcher

I log in as user 1 , then log in as user 2, switch back to user 1 and log out - I return to user 2 but I am now not able to switch user, it takes me to the (Alt-Ctrl-F7) screen, with no login screen.

[Stanley Sokolow (overbyte)]

Also running Gutsy Gibbon (Ubuntu 7.10) for Intel PCs, nVidia driver, all up-to-date.
Similar problem. When switching from user 1 (a non-administrative user) to user 2 (administrative permission user) and back to user 1, I get a blank off-white (or very pale brown) screen with mouse pointer arrow, but nothing else. I got out of it by exiting X using ctrl-alt-backspace, which put me back at a login screen. This blank screen appears to be the same as I get when I switch using Ctrl-Alt-F9. (For me, Ctrl-Alt-F7 gets a black screen.) I haven't tried switching to the X system screen using Ctrl-Alt-F10, but I'll try that and let you know in a follow-up comment.

If I switch user while Firefox still is running a window on user 1, I can login as user 2, but the system monitor shows that some processes are taking a lot of cpu time even though I'm doing nothing as user 2. Running "top" from a terminal window then shows that the Firefox and compiz processes are running and consuming most of the cpu time, doing who knows what in the invisible background instead of sleeping. Maybe the Firefox is continuing to run some animations on the web page it's displaying. When I return to user 1, there is no Firefox window. If I run Firefox then, it starts by telling me that it was not shut down correctly and asking if I want the old session restored or instead to start a new session. So, it appears that before switching user I'll have to close all open windows (not just minimize them).

[Saivann Carignan (oxmosys)]

Thanks for this bug report. and for your contribution.

In order to find which package is the cause of that bug and if we really all speaks about the same bug, can you provide these informations?

1. The output of this command in a terminal : cat /etc/X11/xorg.conf | grep -A 2 'Section "Device"'
2. Can you disable compiz on each user session ( by clicking System / Preferences / Appearance and then select none in the user effects tab ). After Compiz is disabled, can you try to reproduce the bug again, does it appers when compiz is disabled?

[Saivann Carignan (oxmosys)]

Sorry I gave you the wrong command, here's the good one : cat /etc/X11/xorg.conf | grep -A 4 'Section "Device"'

[Saivann Carignan (oxmosys)]

1. Identifier "nVidia Corporation G80 [GeForce 8300 GS]"
        Boardname "nv"
        Busid "PCI:1:0:0"
        Driver "nvidia"

2. This bug only happens with compiz enabled on my computer, it doesn't appear with metacity. It's not possible to reproduce it on my other computer which has a ATI card because compiz just starts on one user session at the time, I don't know if all ATI cards work in that way.

Here's a short video which shows the bug at the end all steps described in this bug report.

http://upload.leservicetechnique.com/bugs/whitescreen.avi

[debianmigrant (debianmigrant)]

Yes it only happens with Compiz turned on and nvidia cards here too.

[Saivann Carignan (oxmosys)]

In Hardy, this bug still happens, I just have to :

1. Login with a user
2. Switch and login with another user
3. Logout from that user session

I get to a white blank screen. If I type my username and my password, I get on my Desktop so this is probably the welcome screen, but I only see a white blank screen.