Great first light result Colin. The ASi1600 is so smooth. Make sure you are running the latest camera driver from ZWO (its linked on the downloads page of the product).
http://astronomy-imaging-camera.com/software/
I would suggest pluging the camera USB3 cable directly into your laptop if possible, second choice is via a powered USB3 extension cable. I assume the one you received has the integrated USB2 hub for the filter wheel.
Suggest you set the USB speed at 70 to start with on the ASCOM driver page, which you can access in SGP after you connect.
Have fun.