I had this with a few of my users. I usually got them to delete some service books ( ALL service books that begin with Desktop; specifically [OTASL], [SYNC], [CMIME], [CICAL] ) , resent the SBs from the server; the device started working again.
6-Time BlackBerry World Champion (2007-2012)
BlackBerry® Certified Support Specialist v5.0
BlackBerry® Certified System Administrator v5.0