Strange behaviour for {JFBCLogin} tag

JongHan,
As noted in the Autotune Error Checker, you have 2 extensions on your site that are including the Facebook Javascript library (it looks to be sh404SEF). We'd recommend disabling the other extension(s) Facebook integration to prevent odd behavior or failing issues.

As for it showing "Log in" vs "Login With Facebook", no, that's not normal. That usually means that the 'other' (Log in) button is coming from another extension. If users are able to login through 2 different Facebook extensions, that will cause a lot of user-sync issues and general confusion. If you know of a specific page with the "Log in" button, let us know. We can look at it to verify if what I said is right above. However, JFBConnect only has one way to set the Login button text (in the com_jfbconnect.ini language file) and that will be used everywhere.. so, the other button likely isn't from our extension.

Hope that helps,
Alex

Facebook looks to have been messing around with their Javascript code on July 4th. They somehow introduced a bug where, if the user has already approved the app, your language string setting for the button is overriden and the text simply says "Log in". It's been reported (with some other issues) in the bug report below:
developers.facebook.com/bugs/110579562419039

We're looking into some other minor things that may have occurred as well with the change (nothing critical so far). The SCLogin module now has a "Button Image" parameter that you can use if you want to set your own custom image. That will prevent Facebook from overriding the string being used.

Sorry for the troubles, and hope that explains,
Alex