The other night I was doing a shoot and one of my PW's wouldn't fire. I was bouncing it off a large reflector and I seemed to narrow it down to the reflector blocking the signal if it was blocking the path (line of sight) to the flash. Now I know the PW's are radio and don't need line of sight however if I removed the reflector it would fire, put it back and it would not... Has anyone had a similar issue??? The odd thing is only one of the flash/PW combos would react this way, switching out stands rectified the problem. Batteries were all fresh.