I took the hints from people in here and gave 'Deep Sky Stacker' another go.
I have processed a Trifid image from tonight in both Deep Sky stacker and Registax.
The image stacked in Deep Sky Stacker is 8 images and 6 darks,
The image stacked in Registax is the same 8 images with NO darks.
Opinions please.
1. Deep Sky Stacker
2. Registax