I can render non-hd videos to dv format, but not hd. All I want is to be able to get a lossless, 1440x900 video (i.e. not HD) for later editing.

Am I missing some encoder?

You might have to render HD footage to HDV format rather than DV format. And if you want to render HD footage to DV you probably have to transcode it to a lower resolution. Just my guess. Might be wrong.