Query Notification Does Not Work Due To Failure To Authenticate The User ?

I tried using Query Notification on my computer at home:
* Win XP Pro with all the SPs and hotfixes
* SQL 2005 with SP1 qand hotfix

Query Notification worked fine.

Then I tried using it at work:

* Win XP Pro with all the SPs and hotfixes

* SQL 2005 with SP1 qand hotfix

and I see the following error in the SQL server log file and notification does not get to the client app:

----------------------------------------------------------
Date 9/1/2006 10:18:30 AM
Log SQL Server (Current - 9/1/2006 10:18:00 AM)

Source spid17s

Message
An
exception occurred while enqueueing a message in the target queue.
Error: 15404, State: 19. Could not obtain information about Windows NT
group/user 'domainmyuser', error code 0x6e.
----------------------------------------------------------

A similar error shows up in the machine's Event Log.

I am
sysadmin and full OS admin on both boxes. The difference is that the
computer at home is standalone while the one at work is part of a
domain.

What could be wrong?