[horde] Horde 5.1.1 problems with ActiveSync on Android

[Daniel Ritter]

I upgraded from 5.0.1 to 5.1.1 today.
Now Activesync doesn't work anymore as expected. Mail syncs fine, 
contacts and calendars do not.
I lost all contacts and calendars on the android devices. They are still 
available in Horde, but don't sync.

I am using two different Android clients for testing, both running 
different versions of Cyanogen Mod.
They used to sync fine with 5.0.1.

What could I do to fix or investigate this?

Thanks.