[horde] ActiveSync trouble

[Stephan]

Hi list,

I am having trouble synchronising my Android phone's calendar with 
horde5. I disabled calendar sync on the phone and reset the sync state 
in my user preferences. Turning on custom logging I can see this in the 
log over and over again:

2012-12-19T22:17:07+01:00 DEBUG: Policykey: 0 verified.
2012-12-19T22:17:07+01:00 DEBUG: I  <Synchronize>
2012-12-19T22:17:07+01:00 DEBUG: I   <Folders>
2012-12-19T22:17:07+01:00 DEBUG: I    <Folder>
2012-12-19T22:17:07+01:00 DEBUG: I     <SyncKey>
2012-12-19T22:17:07+01:00 DEBUG: I      0
2012-12-19T22:17:07+01:00 DEBUG: I     </SyncKey>
2012-12-19T22:17:07+01:00 DEBUG: I     <FolderId>
2012-12-19T22:17:07+01:00 DEBUG: I      @Calendar@
2012-12-19T22:17:07+01:00 DEBUG: I     </FolderId>
2012-12-19T22:17:07+01:00 DEBUG: I    </Folder>
2012-12-19T22:17:07+01:00 DEBUG: Creating new sync_cache entry for: 
@Calendar@
2012-12-19T22:17:07+01:00 DEBUG: I   </Folders>
2012-12-19T22:17:07+01:00 DEBUG: I  </Synchronize>
2012-12-19T22:17:07+01:00 DEBUG: Have syncable collections
2012-12-19T22:17:07+01:00 DEBUG: No HIERARCHY SYNCKEY in sync_cache, 
invalidating.
2012-12-19T22:17:07+01:00 DEBUG: O  <Synchronize>
2012-12-19T22:17:07+01:00 DEBUG: O   <Status>
2012-12-19T22:17:07+01:00 DEBUG: O    12
2012-12-19T22:17:07+01:00 DEBUG: O   <Status/>
2012-12-19T22:17:07+01:00 DEBUG: O  <Synchronize/>

Is this some kind of database trouble ? The 
Administration->Configuration page says that the database scheme for 
ActiveSync is A OK.

Thanks
Stephan