No admin users on Membership Premium

Hi guys,

I've been having trouble with user levels in the Membership plugin.
After altering access levels, I locked myself out of standard Admin-level access to the Dashboard etc even though I'm a Membership Admin user.
Checking the Membership Admins under the plugin options I get this message:

"There are no Admin users - something may have gone wrong."

I tried uninstalling and reinstalling. I've been working on it all night actually.
Any thoughts?

Craig K.