Brian,
Sorry for the delayed response. I just got into your site to investigate things. I switched the only SCLogin instance to use the modal popup so in the menu it worked that way, then tried to narrow down what was wrong.
The issue is fixed now. The fix was to enable the Include JQuery/Bootstrap setting in JFBConnect. That includes a special JQuery and Bootstrap library that is sure to work with JFBConnect. Without it, conflicts between Javascript on your site can crop up and cause issues, like you were seeing.
I don't know what exactly the conflict is, so I can't help there. However, there is one really odd thing I found. The SCLogin module's code is being placed *after* your closing body and html tags. That's not being done by SCLogin. The div it's in is called "codeboxrvbuttonsfvmpj5showb1", so if that helps narrow down what may be inserting the code in the wrong place, hopefully that helps.
I reset the modal setting back to 'normal'. You can change it to modal and test further.
Hopefully that gets you going, but let us know if you need anything else.
Thanks,
Alex