The other evening I was shooting VIPs at the casino and decided it would be a good idea to try using the TT1 with 580EX II on top of a 1DMIII to get better power usage since the venue is darkish. In order to focus I use AF assist. But when I put the TT1 between the camera and flash I no longer got AF assist. I was using the latest Beta firmware in default mode. Is there something I am missing?