kontact & xfce

I'm currently poking around with xfce and kde 4 apps, which works so far quite 
good, but kontact (from kde 4.3.4) shows a weird behaviour:
upon first start, I get the following:

<unknown program name>(1518)/: Communication problem with  "kontact" , it 
probably crashed.
Error message was:  "org.freedesktop.DBus.Error.NoReply" : " "Did not receive 
a reply. Possible causes include: the remote application did not send a reply, 
the message bus security policy blocked the reply, the reply timeout expired, 
or the network connection was broken." "

then, on 2nd try, there is a warning message box which says: kontact seems to 
be running already, start anyway ?
- confirm with yes: kontact starts finally, but always shows a rotating mouse 
cursor.
if I then quit kontact and restart again, all seems to be normal.

can anyone here confirm this/give any hints on how to improve the situation ?

werner