Well, the HDR image is proving problematic.
PS CS3 won't handle the alignment (I think it's aligning on background noise since that covers most of the image), and EasyHDR falls over on lack of memory...
Here is a simple stack, manually aligned in CS3. Normal blending mode. It's amazing how much the moon moves between shots, so the images are aligned on Regulus, Mars and Saturn. I really should do two stacks (one on the moon as well) and then a masked combine, but I just don't think it's going to be worth the effort.
Al.