Cheers guys. I forgot to add that that was just a 70% crop of the original image. The data was too noisy at 100%.
Ross, I think the dark halos around the stars are due to me using a DSLR lens (which isn't really designed for shooting long exposures of stars at night). The halos are there right out of the camera even before I begin processing. That said they can also be caused by over processing images as well but I have the problem of having them there even before I begin processing
Below is a direct link to a powerpoint presentation which I used to remove the dark halos from around the stars using photoshop.
Remove Dark Halos