OWA / Remote Workspace Access Problems

I run a SBS 2003 server. I am having problems with ALL domain
users being denied access to these services. I can access the
log-on page, but when ANY user (even admin) tries to log-on,
they get 1 of 2 things:

OWA – returns incorrect user/pword….
RDC – returns the user to the logon page with no reason
returned

What am I missing here? I have looked at some MS KB articles
that have suggested conflicting access rights possibly coming
from SharePoint, but I have followed the KB fixes, with no luck.
AM now considering removing SharePoint, to be sure, but am
afraid this won’t solve the problem….

Help!!