This weekend I was testing out my new 75mm lens with off camera flash. I couldn't figure out why the flash wasn't in sync with the shutter. It would go off, but it must have been before or after the shutter was open. I tried all sorts of shutter speeds within the syn limit and even tried different sync speed settings. The only thing I didn't get to was trying the rear curtain. Anyway, I finally changed the shutter from silent to anti-shock and magically everything worked like normal. Obviously this is firmware version 4.0 since that is where silent shutter was introduced. Can anyone else confirm the same behavior? Do you think this is by design or constraint?