Feeling rather doltish because I can't figure out if it's me or how I've got things set up.
Configuration: PW receiver connected to 580EXII which in turn is set to Master. The 580EX is set to slave. PW transmitter on the camera.
Problem: 580EX II fires as expected. The 580EX in slave mode however does not fire until after the shutter has closed...at least using shutter speeds that ranged from 1/200 sec to 1/25 sec. I want them to fire simultaneously.
As an aside, when I mount the 580EX II on my camera, both flashes fire just fine.
OK, so what simple, well known precaution am I not taking?