[horde] Database upgrade from horde4 to horde5

[steffo76 at gmx.de]

Hi list,

I am trying to upgrade from horde4 to horde5 and am having trouble getting past the database upgrade. In Administration->Configuration I choose 'Update all DB schemas' and get an error message saying 
>>Query failed: Invalid default value for 'message_uid' ALTER TABLE `horde_activesync_mailmap` CHANGE `message_uid` `message_uid` int(11) DEFAULT"<<

The database for Horde_Activesync stays in the "DB schema is out of date." state.

What can I do about this ?

Regards
Stephan