In case you missed out on Nikon’s site or my Dad’s, there is an update for the SB-5000 Flash. Here is the link and below you can see what was updated.
• Fixed the following issues:
– Zoom (angle of illumination) did not function as expected at low temperatures.
– When AF ONLY (AF assist illumination activated, flash function canceled) was selected for Custum (Custom menu) > AF (AF-assist illumination/canceling flash function), pressing the shutter-release button halfway after restarting the standby timer or after turning on the camera would not activate the AF-assist illuminator.