Charlie Chaplin Judder following iMovie to iDVD to DVD transfer

Question

I've checked the forums but I can't find an answer to this question: I'm sure it's obvious, but I can't work it out.
I've been building an iMovie project for a month or so now. The footage was taken using two different cameras which saved the video in two different formats (.mov and .mp4). So far, no problem. I've built the project and worked with both kinds of file and made some lovely movies.
I've moved the project to iDVD and, still, no problem with playback when using the iDVD preview. However, the finished, burned DVD doesn't work quite right. The movies judder the whole way through, or rather, it's as if every other frame is missing so the movie has a slight, Charlie Chaplin feel to it.
To confuse me further, I have included an 'extras' section on the disc and have put some individual unedited movies (i.e. just the orignal .mov or .mp4 files) in this section. These play just fine, no judder at all, regardless of whether they came from one camera or the other (one format or the other).
My confusion is, why am I getting this judder on my edited movies once they are rendered and on disc? They play fine in iMovie and play fine in the iDVD preview, but as soon as I commit them to disc, they judder, except for the single video files, which play fine, as I said.
I've tried using different DVDs and I have upped the quality setting, but no difference.
I have a theory, but no technical knowledge to express it/work out a solution: could the rendering process be confused because the movies I have made in iMovie include two different video formats? So, when it comes to building the DVD, the Mac messes up rendering the files and renders them all at an odd frame rate?
I don't know... but I'd appreciate any advice!
Thanks!

Answer 1

"..should I expect to get a DVD/Disc Image that is faithful to the original preview in iDVD?.." ..in my experience, Yes!
But your movies were from "..different cameras which saved the video in two different formats (.mov and .mp4).." ..You don't say whether these really were video cameras, or if some of the material came from, say, a stills camera which also takes short movies.
Although a movie may be "presented" - when it's delivered from the camera and brought onto a computer - as a ".mov" (..or even .mp4..) that doesn't describe its actual characteristics, but only the file type in which it's held.
Like delivering a bucket, or a Thermos flask of something to someone: those names describe the container, but don't say what's in it (..a bucket of pig-swill? ..of champagne? ..of milk? ..a Thermos flask of hot tea or of freezing-cold liquid nitrogen?..)
So there may be some peculiarity of the frame-rate of the original material which doesn't take well to being transcoded to a DVD.
Maybe if you could say which cameras were used to shoot the material, or which type of cameras, then we may be able to help more: the original footage may need to be adjusted in some other program such as MPEG Streamclip, or similar, to "smooth out" any oddities before using it in iMovie.
QuickTime should play any .mov file (..it sometimes needs you to buy an extra 'MPEG-2 component' to play some MPEG-2 files..) ..but that's presentation on a computer screen ..so called 'progressive' or 'frame' playback, which is different from the (usually) "interlaced" half-a-frame-at-a-time playback on a TV from a DVD player.
So; where and how and on which cameras did the material originate?