I could be way out in left field here as I haven' tried self guiding yet with my ST 7, but don't you run your guiding from the camera to your laptop via the USB and then back to the mount via serial? Rather than directly from the camera to the mount via the mount port on the camera. I know some mounts you can run direct from the RS232 port of the camera to the RJ12 port of the mount but I didn't think the EQ6 was one of them. I thought the guide chips signals normally come down the USB cable along with the imaging chip signals. That way it should be USB>laptop>serial cable to mount.
