Star "shadows" and banding

[namreg]

Hi guys

Can anyone help with this? I've recently noticed this problem with my images and can't imagine what's causing it. To the right of the brighter stars is what appears to be a reflection, echo or shadow or whatever you want to call it. Also, the very bright stars cause banding (this is NOT an extension of the spikes - on another image the banding was horizontal but the spikes weren't)

Using a 200p with Nikon D70 at prime focus. Baader MPCC and Baader Neodymium filter. This is from a stack of 60 second subs, unguided, and is a very close crop (as you can probably tell!)

Any ideas anyone?

Thanks