Domain Mapping just redirects on first domain I map

I have created my installing a fresh wordpress 3.4, activated multi-site. Successfully created cName sites as a test. Then I installed domain mapping and pointed to displays properly on public page however, when I try to log into it it just gets into this redirect back to the login page. If I enter the incorrect credentials it tells me so, however when I enter correct credentials it just shows me the login page again.