You must first login before you can choose a site to upgrade:

OK,

so here's my problem. I have WPMU installed on TMDhosting.com. 2012 theme is running so avoid any issues. I created my first basic site. In the Network Admin, I choose:
-Pro Sites
-Settings
-Checkout Page
-Edit Checkout Page.

Everything seems ok, I can create, modify and edit the page. If I go visit the page, I get the:
"You must first login before you can choose a site to upgrade:"
Username ____
Password ____

can anyone PLEASE help me understand what I should do to not need a signup here??

My Model -
The main site is visible at all time.
User purchases the blog and I create things manually
(I believe that's easier because I'm having issues with the themes and plugins duplicating in all site!! )

Thank you very much y'all!!