Frames are blended together? Wha-? Huh-? Geh-?

Hi, I am importing DV from Avid Xpress Pro into Encore 2.0. I shot it on an XL2
at 24p advanced. (I think I finally understand everything about how this will
end up as 29.97 interlaced with pulldown flags on the DVD). Footage looks and
works fine in Avid. I am transcoding in Encore.

After Encore transcodes, each frame of my movie is clearly two different frames
dissolved together! It's visible in the main preview pane, and on the finished
DVD. This is VERY obvious in motion onscreen and cuts between scenes.

A few things to note: I don't think the problem is 'in' the exported footage
from Avid. Encore has a preview window when you "Edit Transcode
Presets" and the clip does NOT display the problem there, even after it's
been transcoded and already has the problem in the main preview pane. Also, this
does NOT happen to this clip when it was exported/imported as 29.97. So it only
happens when Encore transcodes an asset that it considers to be 23.976 (whether
it's QT Ref or movie file). Problem is, I want my 24p movie to have pulldown
flags on my DVD!

I changed transcode field-order settings from Progressive to both Upper and
Lower frames but no effect. I can't figure out how this would be happening -
there are actually fewer frames at 23.976 than at 29.97. The footage is being
stretched timewise. So if anything, I should see frames repeating after
transcoding, not being combined!

Is it possible this is because I shot/edited with 2:3:3:2 pulldown, but
progressive DVDs just have 2:3? In other words, I shot it advanced, but DVDs are
standard?

If I can't solve this, I'd be happy if there was a way to make Encore force a
clip to 23.976 (in other words, adding pulldown flags) even if it came in at
29.97.