Tammy,
Couple of things I found with my original setup - 8"SN and Neximage was :
1. Focus. Does your OTA have a single speed focuser or dual?
2. Consider increasing your F ratio. It was recommended to me by a fellow IIS member to change from my native F4 to something like F7 by placing a black piece of material over the front of the scope and cut away say a 2" hole. The moon is bright and you don't change the magnification but my focusing was easier. I got sharper images that way.
3. Neximage. Your images appear over exposed. Back off the exposure and reduce the gain if possible.
Good luck!!
Darrin...