Real-Time manager connection failing with credentials error

When using Real-time manager I keep getting
"Can't establish connection."
"Provided credential are not valid." on the connect screen. I have setup a profile with a domain admin that is defined as a local administrator of the computer I'm trying to access. I have also tried keying in the user name and password on the connection screen also with the same results. Does anyone have a idea what I could be missing? Thanks