Error: You do not have sufficient permissions to access this page.

Hi, I just updated the NBT plugin and now I'm getting the error above. This is what happens:

1. Sign up and activate a site like normal
2. Try to login to the site admin, and I get the error

I have deactivated all other plugins, and I'm using the default Twentytwelve theme. I have isolated the problem to NBT. The signup process works fine without the NBT plugin, but once I activate it, the login error happens.

I am using WP 3.5. Please help, thanks.