Originally Posted by
GrumpyDiver
George - in those shots the flash used was not capable of FP/HSS, or in fact even communicating with the camera. The camera was set so FP/HSS was enabled (at 1/250, as per the instructions by PocketWizard for Hyper-Synch), as that is the only way that speeds higher than synch speed can be selected on the camera. The PocketWizard FlexTT5 was set so that FP / HSS was DISABLED.
My guess is that this is reported by the camera when it detects a flash is used and the shutter speed selected is higher than the synch speed of the camera.