[horde] ActiveSync - username empty

[pz]

Hello!

I have a problem when I try to connect to activesync with a Nexus S
(Android 2.3.4). I have the newest Horde installed with pear. I didn't
try any other activesync-clients because i have only this one.

IMP is doing authentication.
My username is the full email-address.
I habe a valid ssl-certificate and I am running apache2.

Horde is installed in  https://s0medomain.de/mail
The email-address is:   bla at 0therdomain.de
The emailadress starts with 0 but another address also didn't work.

Configuration on android-device:
Domain/Username: bla at 0therdomain.de	
Server:		 s0medmain.de
Use SSL Connection: YES


horde4-activesync log misses username:
2011-05-22T20:39:27+02:00 INFO: Horde_ActiveSync_Driver_Horde::logon
attempt for:

no new entrys in horde4.log

my mail.log file has also no username:

  May 22 20:39:27 tesla couriertcpd: Connection, ip=[::ffff:127.0.0.1]
  May 22 20:39:27 tesla couriertcpd: LOGIN FAILED, user=,
ip=[::ffff:127.0.0.1]

Apache2-log:
[22/May/2011:20:53:40 +0200] "OPTIONS
/Microsoft-Server-ActiveSync?Cmd=OPTIONS&User=bla%400therdomain.de&DeviceId=validate&DeviceType=Android
HTTP/1.1" 401 - "-" "Android/0.3"

There is the email-address. Somewhere it gets lost.
Does anybody know how to fix this problem?

ps: Same problem with an address mail at s0medomain.de

kind regards
pz