I really hate to say this, but you might have to just blame it on
being a beta product. You might have gone through a series of steps
that Microsoft didn't intend on yet, which could cause this issue. I
would also recommend that you upgrade to the Technical Refresh, since
you mentioned you had not upgraded yet. If you have the resources, I
would recommend reinstalling your OS or setting up another dev server
and trying again. I can't tell you how many times I've installed
MOSS in the last month.