Domain mapping error "Could not determine user from environment"

Hello

I am having difficulty in getting the domain mapping plugin to work. The page and error I get is below...

Could not determine user from environment: http://lancesonka.com/cgi-sys/defaultwebpage.cgi

This is a recent wpmu/buddypress install @ psek; all install and domain instructions have been followed including removing // @ wp-config

The original blog is lancesonka.builderpress.com mapped to lancesonka.com

Your consideration is appreciated, thanks.

Lance