Andy is this a the full frame from the camera or a crop to one side? It looks like something in the scope is misaligned. Notice the stars are sharper on the right than the left? Or if it's just a crop from the side of the image then it's really just a case of a flattener.
Also your image has a bit of a green tinge. There's a free plugin for Photoshop that nails it in one button press that I used early on here:
http://www.deepskycolors.com/archivo...sta-green.html
Otherwise a respectable shot!