local client: Failed to get a message, terminating

Hi,

I just upgraded our hobbit server to 4.2.0 and installed a local client 
on a linux machine. Everything seems to work well, but every 5 minutes 
the client logs the following message in its hobbitclient.log:
"Failed to get a message, terminating"
What could be the cause of this message?

P.S.: thanks, Henrik, for this great new release :-)

-- 
Best wishes,
Dirk Kastens