suddenly, getUser became to return 0.(PHP 3.1.1 SDK)
I think this is a Facebook bug, I just finished figuring it out myself. You need to alter the Base_Facebook class, and add in a new query param to strip out. The base_domain param is being accidentally appended to the redirect url, hopefully a fix will be rolled out soon.
/** * List of query parameters that get automatically dropped when rebuilding * the current URL. */ protected static $DROP_QUERY_PARAMS = array( 'code', 'state', 'signed_request', 'base_domain', // this is the one you need to add );