Please provide a link to your site where we can see the behavior in action.
Usually when this happens, the common causes are problems with javascript compression on the page or JQuery. Could you try temporarily disabling any optimizations for compression that you may have enabled on your site, changing the parameters for JQuery in the SCLogin > Advanced section and then re-trying? Additionally, please look at the error console in your browser to see if there are any Javascript errors that appear. This can be helpful to identify the problem too.
-Melissa