I just pulled out my old Strobist gear (well, it was before there was such a thing as the Strobist blog, but same idea) and tested it with my GF3. I've got an Achiever 632T connected to a Wein peanut slave. The flash is properly triggered by the GF3's built-in flash (I can see it fire), but only the faintest of glows is visible in the picture, and the overall exposure is pretty low. I assume this means the pre-flashes are triggering the peanut prematurely, causing the camera to think there's more light than there actually is, and then by the time the camera actually fires the glow from the remote flash has mostly faded. So how do I turn off pre-flashes in the GF3?