I also don't know how to check which other modules may be loaded this way.
I mean try an ID of another module in the load tag instead of the ID for SCLogin {loadmoduleid 173} This will help to narrow down whether it's just a tag problem or something with SCLogin
Also, I've never used loadmoduleid; I use loadposition or loadmodule. See
here
. You could try one of those as well. You'll just have to set a position for the module.
Finally, if you temporarily disable all of the JFBConnect plugins and attempt to load a different module with the tag and it's still not loading, that'll show whether or not it's not related to JFBConnect/SCLogin.
-Melissa