In the SCLogin module, if you have the "Show Connect Account Button(s)" setting enabled *and* the user isn't currently logged into Facebook.com, the "Connect this account?" and Facebook buttons will appear. That's there to let the user login with Facebook to enable Open Graph or other features that are Facebook dependent.
I can see where that may be confusing though, and we're actually discussing some changes to that functionality right now. If you don't like that, I'd recommend disabling the "Show Connect Account Button(s)" setting for now.
I hope that helps explain,
Alex
SCLogin module asks to connect FB every time
