I have the STI8300, bought as the filter wheel and AO pkg, using M-DL pro. When doing an auto dark exposure, the auto dark subtracted images come out black, no matter how I stretch the image: As though the shutter doesn't close when taking the dark frame, and it's subtracting a light from the light frame. No alarms come up. I can manually create and subtract dark frames. I use an st-402 as a guider, and it's auto dark function works fine. If I Switch the 8300 & 402 btwn camera 1 and 2, the problem follows the camera.