I'm perplexed. With my BD burner freshly installed, I've burned two project to BD and they came out the berries, so all is good there.

Where things start going pear shaped is using Encore to output the same project to SD DVD. One project was shot and edited 60i and the second was shot and edited 24p. Both SD DVDs were created deinterlaced, preserving the source frame rate. The first project (60i) exhibited interlace line issues that I'm still wrestling with, but I can see how there could be issues if I don't deinterlace early enough in the workflow.

It's the second project (24p) that has me all confused because it is exhibiting the exact same "mice teeth" problem as the first project. I don't see how that's possible since nowhere along the workflow does the footage get interlaced. At least not that I can see. I specifically used a custom transcode setting with the following parameters:
Quality: 5
Frame Rate: 23.976 (24 is not an option)
Field Order: None (Progressive)
PAR: Widescreen
Bitrate Encoding: VBR, 1 Pass
Min Bitrate: 1.5
Target Bitrate: 5
Max Bitrate: 9
M Frames: 3
N Frames: 15
Deinterlace: Ticked

The DVD looks great except for the mice teeth. Can anyone see what I'm doing wrong here?

OK... I'm still perplexed but it's now narrowed to the thought process of the Adobe developers.

I have found a potential solution that apparently works for other people here: http://invertedhorn.axspace.com/hdv2dvd_basic.html

I have long been aware that sometimes you need to subvert the normal Adobe workflow to get the desired results. I found a link to the above URL on the Adobe Encore User forums. Apparently it's been useful for a lot of others since the thread has 250 posts at last count. Virtually unheard of for an Adobe forum.

I'm going to give this workflow a go tomorrow and see how it works. And I'll go on scratching my head as to why the folks at Adobe didn't thing that any of us users would want to output a single project to BD and SD. It's rather pathetic really.

Tripp,
that's an extremely convoluted workflow that resembles to computer hacking rather than video editing. The shortcomings of PPro/Encore have been beaten to death on this an pretty much all other video forums, just search around. Bottom line is, virtually no one is happy with the downconvert results. You need a better encoder to handle this task in one single pass OR you need to downcovert/resize using VirtualDub, then encode to mpeg2.

Tripp,
that's an extremely convoluted workflow that resembles to computer hacking rather than video editing.

Yeah... ain't that the truth.

It's interesting, however, that "frame serving" out of Adobe applications is not all that uncommon a workflow. It may also be the most seamless solution for converting HD to SD DVD. It also may not be, but I'm going to try it. I'm also going to look into your suggestion.

What I ultimately want to do is eliminate, as much as possible, the re-authoring of all the DVD bits. If I can reuse all of the work that went into the BD authoring, even if the workflow is a bit of a hack, I'll definitely come out ahead.