asterisk users - Aug 2011 - subscriptions from ekiga to asterisk

Hello List!

I have small but strange problem with ekiga 3.2.7 (on Debian Squeeze as
well as on Win XP). For every contact I have listed in ekiga that has a
corresponding hint in the dialplan ekiga tries to subscribe to the hint
but fails. In asterisk the a message like this is shown for every
contact in ekiga:

[Aug 30 23:25:55] NOTICE[30755]: chan_sip.c:21489
handle_request_subscribe: Failed to authenticate device "Michael
Hauptfeld" <sip:michi at
10.8.0.6>;tag=867d4550-bcd1-e011-94fe-f4ec38ab651d
for SUBSCRIBE

I wonder why there is "... <sip:michi at ... " as I have
"michi" nowhere in
my ekiga setup, nor do I in the asterisk configuration.

In the extension.conf I have the following for most numbers:
[...]
exten => 210,hint,SIP/210
exten => 210,1,Dial(SIP/210,${INT_RINGTIME},tTxX)
exten => 210,n,VoiceMail(210,u)
[...]

In sip.conf:
[general]
...
;allowsubscribe=no              ; (Default is yes)
;notifyringing = no             ; (default: yes)
notifyhold = yes                ;
notifycid = yes                 ;
callcounter = yes               ;
...

[int-std](!)
type=friend
secret=somesecret
host=dynamic
nat=no
subscribecontext=default
call-limit=10
canreinvite=no
callgroup=8
pickupgroup=8

[210](int-std)
callerid=Hennes <210>
secret=...
[...]

I'm running Asterisk on Debian Squeeze from the debian repositories.

I don't know whether this is a problem of asterisk or ekiga. Seems to be
ekiga, but I hope somebody can help me here.

Sincerly,
Michael