Graeme,
The SCLogin module drop-down menu uses the Bootstrap Javascript and CSS to create that effect. I'd start by trying to enable the "Include jQuery" setting in the Configuration -> Misc area of JFBConnect. Hopefully, that's all there is to it.
Also, please note that the menu in our top right is using the SCLogin module, but our template applies special styles to it to make it look like that. We can help you try to achieve the same 'blended' effect if you'd like as well, but lets get the drop-down working first. For a better example of what the default user menu looks like, see our
Improved Joomla Login
JED listing. The last image in there shows the default look for the User Menu.
I hope that helps explain and get you going,
Alex