I am using Yoo theme and unable to make the gallery(slider) work....

Is this a module or something of the sort provided with the template? Sounds like a jQuery conflict perhaps. CB runs jQuery in noConflict mode and typically is not affected by conflicts, but same can't be said for other extensions.

Also once logged in, there is only facebook signout button, no website log out button...please help.

Working as intended, you have to logout through FBC if you sign in through FBC.

if I disable the FBC it works fine... please help me here....

Of course, because FBC loads CBs jQuery library. However, FBC continues to function as CB loads its jQuery in noConflict mode.

P.S. I have enabled no conflict in FBC plugin

This is to help avoid conflicts with other extensions using Facebook API, has no relevance on jQuery conflicts.

You need to contact the developer of your module for further assistance. They need to be using jQuery in noConflict. The best approach is to route their instance of jQuery to their own selector like "var jSlider = $.noConflict( true );" then they'd use "jSlider." instead of "$." or "jQuery.".