Intermittantly the 580 flash acts as if the 5D2 is a non-compatible camera and reverts to "TTL" and full power. Some times turning on and off, going to flash mode on camera and back fixes it, sometimes not. Really can't tell if it's a camera or flash problem.
Is there some setting in the camera or flash i've inadvertantly screwed up? This is a new problem and i've used the flash on a couple other bodies and the 5D2 for some time without problem.