PLEASE HELP...facebook login button not logging in suddenly.

It's tough to know what's wrong without knowing the modifications you've made, and that's also worrisome. If you've modified template files only, you should try using template overrides for those (storing the default.php file from mod_jfbclogin in /templates/YOURTEMPLATE/html/mod_jfbclogin for example). If you're modifying the controllers or models, we'll definitely need to know what changes you've made to help out.

I just created an account from Facebook and logged out and in multiple times. I coudln't see the issue you describe. Is it only with one specific user you're seeing the problem? Does it depend which page I'm trying to log in from?

Any other information you can provide to narrow down the bug or recreate it would be terrific.

The calls go over to Facebook. There's only so much we can do about their response times, which is where some of the delay comes from. Additionally, if you are importing the profile and avatar on each load, that requires extra calls to Facebook to retrieve that data. We try to minimize the calls, and are always working on ways to optimize this process. I'd recommend trying with minimal importing of information to see if that improves your speeds (only on registration, not each login, etc).

The plugins were disabled (and now removed) as they are installed and upgraded with the component on installation. The amount of files we have for JFBConnect is already too large, so including extras that are already in the component just adds to the confusion. We also removed the JFBCLogin module. If you ever need these individually, they are in the /admin/packages directory in the main component zip file.