Quick questions to all those who have experience with shooting on a digital back with Mamiya RZ67 ProIID, via the HX701 adapter. Which position should the R-M lever be on the camera body? I have received the back today, so just getting familiar with the setup. My problem is that the shutter does not fire when it is in the central dot position, where it should be using film backs. Only fires when the lever is on the M position (multiple exposure). Is this the way it should be? I have downloaded both the camera manual (no mention of digital backs whatsoever) and the IQ280 manual but this is not mentioned anywhere. Or am I looking in the wrong places? (Memo: The back is set to the RZ67 Pro IID mode). Many thanks in advance.