One of the major concerns with running a leaked version of OS 5.0 has been the fact most RIM designed applications were not yet compatible with OS 5.0. FaceBook is of course one such application that until earlier tonight was among the non working applications, but RIM has rather quietly updated FaceBook to version 1.6.0.22 which does indeed make it compatible at this time. So if you have been running any of the leaked version 5.0 operating systems and been missing FaceBook you can grab the updated version and be back in bu