There is nothing wrong with your results from DSS, Chris.
You just need a bit of processing in DPP - see here (this is how I do it):
http://www.iceinspace.com.au/forum/s...nal+DPP&page=2
Go to #37
Also, on this post-processed image it is visible now that you have vignetting issue (can be sorted out with flats) , and a bit of gradient (LP? could be removed with Iris maybe)