No experience with Crestron integration on that panel, but you may want to check how often you're polling the 128FBP.  If polled too often that panel goes all stupid and doesn't know how to act.  The dialer stopped working when 232 was connected to an Elan system (with their pre-built driver).  Unplug the 232 and the dialer works again.  Hardly makes any sense, but they did nail it down to being polled too often.  Supposedly a later chipset on the 128FBP panel helped, but we never tried...we just disconnected the 232 and put a regular keypad up...