Tvheadend

Hi there
I dont know if this is a XBMC or a tvheadend issue or maybe my wrong understanding of how recording works.
Sometimes I dont want to record a whole show but just instant record some scenes/news and press the record button to stop after some minutes. After that I am not able to record again, XBMC telling me something about "could not save timer". Error Log gives the following:

15:56:55 T:139784945137408   ERROR: AddOnLog: Tvheadend HTSP Client: ReadResult - command failed - Could not add dvrEntry
15:56:55 T:139784945137408   ERROR: PVR - AddTimer - addon 'HTS Tvheadend:127.0.0.1:9982' returned an error: rejected by the backend
15:56:55 T:139784945137408   ERROR: PVR - AddTimer - cannot add timer to client '1': rejected by the backend

My system is
XBMC 14.0-ALPHA1 64bit
HTS Tvheadend 3.2
Tvheadend HTSP Client 1.9.27
on gentoo

any suggestions?