How to handle HD footage?

[Joost Zeeveneegelbeek]

I edited HD video in Pro9 and it looks great. But when rendered as DV Widescreen, Windows Media Player shows lots of pixeling, smudging and unsharpness. I changed properties to progressive scan where needed, but this didn’t change it. When rendered as HD it shows a shadow in motion which I can not loose however I render it. What can I do?