akonadi server is not stopped by logout from kde 4.1.85. As a result, additional akonadi_control and akonadiserver processes are created on each kde login, the old ones have to be killed by hand. A temporary workaround is to put "akonadictl stop" in a script in ~/.kde4.2/shudtown/
Is this still valid for some more recent versions 4.2.4?
With 4.2.4 it is OK, so the bug can be closed.