Windows 2008 R2 DC NTP sync with Debian 6

When a Debian 6 is configured to use a Windows 2008R2 DC as its NTP Server with the follwong line @ ntp.conf
server w2008r2-DC, ntpq -p will display it as a peer, reachable and with correct offset. But the * will never appear, meaning its not synchronising with it.

if you stop the ntp daemon and do a ntpdate -d w2008r2-dc,  this is what you will  get:

It is obvious that Debian does not like the NTP packets coming from the Windows box and is droping them.
So I try using the Windows box to sync from the Debian box:
Windows box 2 registry entries:
1st->




192.168.1.130 is the ip address of the Debian box

  2nd->

and then on the Debian box, nrp.conf:

service ntp restart

and on the Windows box event viewer :