It may be "unavoidable", but I'm not convinced yet. If anbody else out there in empeg-land has a progressive DVD setup and the extended LotR movie, I'd appreciate if they could check this scene out and post what they see.

(Footnote: an unexpected benefit of having a CRT projector instead of a plasma screen / LCD projector is that interlace modes are still natively supported. If you've got a fundamentally progressive device like that, then if your deinterlacer is screwing up... you loose!)