Time to start at the start again and go through all your steps, from camera settings, to strobe settings and all equipment connections.
*Check camera flash setting. Make sure it isn't set to Red Eye or something odd that will affect sTTL sync.
*Assuming a possible issue with optical cables, did you check both ends of cable?
*Have you removed the ACC magnet to see if it is corroded and the possible issue?
*Check over all camera settings with others using the same. Lots of info on your camera here- http://wetpixel.com/...showtopic=52608