AHaaahh
I see that now Justin, your a good man
Ill have a go next comet capture as my recent ones were not exposed long enough (just tracking) and my collimation was knocked out which resulted in a rather diffused comet nucleus, actually no comet nucleus in the subs at all, so the DSS Comet selecter could Not find it to register ? I think that was what was going on ?
I should have a go and lift levels around the comet on individual subs to produce a Nucleus and then throw them in for a stack
Might work
Cheers for your help pointers Justin