Alt-tab works only some of the time when using dual screen with separate X window.

[naranek]

The problem: Alt-tab opens the cover switcher about one out of three to six times.

I tried setting the alt+tab shortcut to perform mute to see where the problem is, and it worked perfectly. So it seems that the keystroke is recorded, but cover switching isn't activated every time. I tried disabling the effect (Effect for cover switching: None) but it doesn't help.

This only happens when I have the dual screen set up using Separate X screen. In Twinview clone mode alt-tab works perfectly.

I'm using a Nvidia GT 9600 card with proprietary drivers from ubuntu repository.

This bug was present at 11.04 and followed thru to 11.10.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: kde-window-manager 4:4.7.1-0ubuntu5
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic-pae 3.0.4
Uname: Linux 3.0.0-12-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu3
Architecture: i386
Date: Mon Oct 24 21:34:20 2011
ExecutablePath: /usr/bin/kwin
ProcEnviron:
 LANGUAGE=en_FI:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: kde-workspace
UpgradeStatus: Upgraded to oneiric on 2011-10-13 (11 days ago)

[dzs (dzsabor)]

I've the same problem. It started after shortly after upgrading to oneiric (today's kde updates). It happens with all kinds of task switching animations/tools (even with desktop effects turned off).
I also have a dual screen setup on an nvidia GeForce 9500 GT (not twinview, using nvidia-current 280.13-0ubuntu6).
Alt-tab works more like 1 out of 15, very annoying...
I wonder why it works sometimes?? It's like two (multiple?) programs are competing for the same shortcut??

[naranek (jarmo-lahtiranta)]

I sometimes find that the krunner is open in the background and it seems to have a tab character inside. I've included a screenshot where I've selected the tab, so it shows up as blue. Could the krunner somehow catch my alt tabs?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[alexander.leshkin (alexander-leshkin)]

I have the same issue. And this one is reproduced only when separated screen configured. And I see some activity on the second screen (TV) when pressing alt-tab.

[Harald Sitter (apachelogger)]

Hi there!

Thanks for reporting this bug! Your bug seems to be a problem with the KDE program itself, and not with our KDE packages. While we appreciate your issue, it would be better if it was tracked at https://bugs.kde.org, so that the KDE developers can deal with this speedily and have direct communication with you as the reporter for more effective debugging.

Thanks!