I think the answer from the staff is palringo :
Tom replied on 06 Nov 2009 @ 15:37
We are aware of the issues with facebook and are working on getting it fixed quickly. We do think facebook has changed some protocols on its site and we need to update Palringo itself to match them.
same case in palringo forum -> iphone
Semoga aja gak terlalu lama masalah ini berlanjut.