BigWill - you might want to check your 3:2 pulldown settings on your DVD player in case it is not automatically invoked. I'm also not familiar with your specific TV but you might want to check if it has 3:2 pulldown and how it works when fed a 480p source so you are not applying the processing twice. Also, are you using any format conversions on the DVD player/TV to expand the picture to remove black bars? Does your TV upconvert 480p to 540p or 1080i? These types of processing can also have an effect on the picture as you describe.
I've got Solaris coming from Netflix in the next couple of days so I'll have a look to see if it is a mastering issue with the DVD, but as I've said before, I've never noticed any artifacts that were not part of the content on any DVD I've watched. I have a Sony 9000ES DVD player piped into a 65" Mits native 480p, but I also apply no processing from the DVD or TV except for the 3:2 pulldown on the DVD player.
Cheers,
Doug
