OWA 2000 (ServerName.Domain)\Username Issue   

I am running Exchange 2000 SP3 with OWA enabled on SSL.

Windows XP clients are starting to show (exchange server name)\username when 
trying to login while others are able to login using just their username and 
password, no domain name prepended to the username.  Why is it trying to hit 
the Exchange server for authentication?

date: Fri, 26 Oct 2007 12:23:01 -0700   author:   MPaquette