Marketplace loop/redirect error

Hi I just installed marketpress at and I am getting the following error while trying to checkout
The page isn't redirecting properly
This webpage has a redirect loop.

The webpage at has resulted in too many redirects. Clearing your cookies for this site or allowing third-party cookies may fix the problem. If not, it is possibly a server configuration issue and not a problem with your computer.

This is not MU.
Any Ideas?