akonadi/kmail is stopped at first start after login

[Martin (KDE)]

Hallo

I have updated my F14 to 4.6.1 from kde-testing and now i got an error 
that akonadi had an error at last run if I start kmail the first time 
after login. In the error logfiles I got the message

D-Bus session bus went down - quitting

I had this error once with 4.4 KDE. Is this a known problem with 4.6.1 
(regression)? How can I go around this error?

Martin