I am close to a hard attack. I was out and about with my Mamiya today and all of a sudden my shutter speeds are all whacked up. Either it will not fire at all, or will stay open for 4sec regardless of the setting and regardless of the lens. Anyone experienced an oddity like that before? Everything else seems to be fine. The meter works properly, even the self timer works, but the shutter speed goes for 4 seconds regardless. Did the electronics in my camera just die? Help !!!