I am started to suffering from that a few days ago. KDE 4.9 from arch linux repos. All work fine after KDE start up and becomes weird after running amarok. It doesn't want to start at all, but after that all system behaves strange. If I will try to select some text in yakuake or konsole they both hangs. Dolphin and also all kde applications are affected. Kwrite, for example, remain fast but File → Open dialog take about few minutes to appear and then few minutes until it become responsive. At the same time I don't see any high CPU usage. If trying to run amarok from console it show: QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave. QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave. Reproducible: Always Steps to Reproduce: For me this happens every time after I trying to run amarok. Once it also happened after I clicked on a link in kmail. 1. Run KDE 2. Check that everything works okay 3. Run amarok (it will not start) 4. Run dolphin, it will take about 3-4 minutes to start (but then works normally). All "open file" dialogs (even from gogle-chrome) take about 3-4 minutes before they will appear and become usable.
Adding Amarok developers into CC list
Just now clicked on the link in kmail (to open this bug report page) and all happened again. Seems like the problem is in the dbus-daemon or somewhere else, not in amarok.
This message: QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave. QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave. also appears when apps works normally, so seems like they aren't related to the issue. Also just restarted KDE, launched kmail, clicked the same link and it works fine.
Looks like this is related to glib. Just tried to comment out this line: export QT_NO_GLIB=1 in my /etc/profile and after that KDE freezes even when I trying to open start menu.
Killing kded4 return things to life. It's even possible to killall -9 kded4, run all required apps and then start it back.
I tried to create new user and logged in to KDE and it worked fine. Started to removing folders from my ~ and looks like removing .thumbnails fixed this issue for me. I was renaming only folders with names that I don't know about, like .pki, .swt, etc, but removed the .thumbnails one, logged in to KDE and it worked fine. So I logged out and restored all renamed folders except .thumbnails one that has been deleted, logged in to KDE and it still work, so I suppose it was ~/.thumbnails.
I had the same problem. KDE 4.9.1 here. Killing all kded4 solved the issue in my case!
Could you check if disabling muon-notifier solves the issue? See also bug 307049. If this does not solve it, you would need to find out, which kded module causes the issue. For more information, see http://kdepepo.wordpress.com/2011/05/11/troubleshooting-kded4-bugs/
I've just upgraded to KDE 4.9.3 and the problem appeas again. Killing kded4 solve the problem. But I haven't muon-notifier in my /usr/share/kde4/services/
Also just tried to disable all kded4 services, but it still hung until nit killing kded4.
Finally, removed ~/.pki and ~/.pulse, restarted KDE and it works again.
Can we close this? It hardly seems relevant today.
Closing this 5+ year-old bug as KDE 4 is no longer maintained.