Optimal iMovie HD settings for YouTube

I use iMovie HD. I really envy the export to YouTube option on iMovie '08, but that isn't an option because the program won't run on my PowerBook G4.

I'm having trouble figuring out the best settings to use for exporting video from iMovie that is meant for uploading on YouTube. The custom/expert sharing option has an overwhelming amount of choices, but none of the presets (i.e. CD-ROM, E-mail) seem good either.

I'm trying to get the highest quality video while remaining inside the maximum size limits imposed by YouTube.

Here is a recent attempt:
http://www.youtube.com/watch?v=6sfXrbggV5Y

As you can see, the frame rate is choppy... the transitions look horrible.
The file did NOT look this way before it was uploaded to YouTube.

Does anyone have any advice? Links to online tutorials would be helpful as well.

Thanks!

There is a tutorial on YouTube, but that hasn't helped me much either - the quality improves but the frame rate does the opposite. I am surprised you have not had any helpful replies to this so far, I would have thought this a most valid and common question on such a flagship Mac Forum.

Anyway, for what it's worth, here's the link: http://www.youtube.com/watch?v=fr82Rl_CTWY