Version: unknown (using 4.4.3 (KDE 4.4.3), Kubuntu packages) Compiler: cc OS: Linux (i686) release 2.6.32-22-generic Kubuntu 10.04 x86 Qt: 4.6.2 KDE Development Platform: 4.4.3 (KDE 4.4.3) kde4-config: 1.0 I have had an issue since 4.4.2 where switching to the Summary page appeared to cause Kontact to hang but upon further investigation its seems the problem is nepomuk. I ran top while doing the switch and observed neopmuk, virtuoso and dbus-daemon consume nearly 100% CPU between them, this lasts approx a minute before they drop to normal and the switch completes. Switching back to another kontact tab (kmail etc) does not consume any cpu or block. I'm pretty sure it used to be worse - kontact would block indefinitely which is why I presumed it was hanging as opposed to being really slow :) My summary view has all the plug-ins activated.
I can confirm this observation with KDE SC 4.5.2 and kontact 4.4.6. It takes about 5-10 seconds before the summary appears, up to half a minute for the very first time. During that time ksysguard shows heavy nepomuk/virtuoso-t cpu usage. I don't have all summary modules enabled, only mails and planner + events + birthdays for the next 7 days, therefore the delay might not that drastical.