Don't Forget to Reboot
You might think it's kinda strange to say "Don't Forget to Reboot" to Linux users as those saying should be said to Windows users, but this happened to me when i upgraded to KDE 4.6.2 using AlienBOB's package in my new Slackware 13.37 installation in my office. I rsynced my local repository and then upgraded using SSH remotely from my house last Saturday.
I haven't tried to run KDE since then until this morning. I got several KDE crashes and i didn't see any useful information at the error messages. I have make sure that every .new config files has been merged, but still persis. Finally i re-checked the README that comes with KDE 4.6.2 by Eric himself and in the last part of the README, it says Then reboot your system.
I was like . I forgot to reboot the system since i upgraded KDE. I remembered that i have rebooted, but it was due to new kernel compiled, not because of KDE update.
Now, everything seems to be working just fine. Akonadi didn't crash on me and even though the indexing was turned on, my system didn't have any performance issues at all.
This post is supposed to be a personal reminder for me, but it would be a good thing if it can help you as well