Sorry you are having difficulty. I Googled and found this:
Pretty simple issue as it turns out. The flash has way more leverage than the bracket can stand over time. As such, it bends up the flat sides of the camera mount and the flash wiggles inside slightly. It's just enough to cause an electrical short between the camera hot shoe and the flash and it sends a signal to the flash to fire. All I did was carefully tweak the hot shoe so that it would be tighter when the flash slid in. Now that I've done this, it made me come to the conclusion that the way Nikon does their hot shoe mounts is pretty friggin' stupid.
It was submitted to Model Mayhem site by 'Shot-By-Adam'.
Hope it helps. Terry.
"The Nikon did the work; I just happened to be behind it at the time." TP