Not all facebook apps work with KM. As is the case with many web designers, IE and Moz FF seem to be about the limit of FB's mentality.
FB seems to have so much recurring amnesia when it comes to maintaining the membership's personally identifiable data that I personally have dumped FB altogether. The scumball's seem to have even booby-trapped my option of permanently deleting my account and wont even respond to my troubleshooting query's. AFAIAC'd FB is really becoming one of the real scourges of the WWW.
~~If it ain't broke, why screw it up?~~