Version: 1.13.0 (using 4.3.85 (KDE 4.3.85 (KDE 4.4 Beta2)), Gentoo) Compiler: x86_64-pc-linux-gnu-gcc OS: Linux (x86_64) release 2.6.31-gentoo-r6 Since two weeks ago or so (after the 4.4 eta2 update) Kontact often becomes dead slow and dbus-daemon takes all CPU time it can get. I think the change I did was disabling CONFIG_SYSFS_DEPRECATED in the kernel (KDE SC 4.4 beta 2 on GNU/Linux via Gentoo). The other option is that the 4.4 beta2 is the reason (though beta1 didn't create any performance problems). It mostly appears when downloading new mail or trying to write a mail - especially when I write to many people. Possibly also related: My nepomuk doesn't really work (indexer doesn't work) since I enabled redland in the compile again (via Gentoo USE flag "redland").
I still have the problem after rebuilding everything without debug, so it seems debug wasn't the reason. To illustrate the severity of the problem: Sending a mail currently needs between 1 minute and 30 minutes between clicking send and seeing the GnuPG "enter password for your key" dialog (yes, "minutes").
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.
Thank you for taking the time to file a bug report. KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2. We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.