asterisk users - Oct 2009 - SIP RealTime defaultuser Field Cleared

Hi All,

I am running Asterisk 1.6.1.2 with realtime for SIP and recently
noticed the values in the defaultuser field have been "disappearing".
I can't place my finger on what is happening but it appears that when
the peer de-registers the defaultuser field is cleared.

I will be having a more detailed look through the logs and possibly
add more logging to the database but wondered if anyone else has had
this problem.

Kind Regards
Stuart Elvish