I'm not an expert on this, but can offer a few suggestions:
1. Drag your uncompressed 24p master into MPEG StreamClip, convert to 29.97, and see how it plays.
2. Convert your 24p footage to 29.97, and save to a separate folder, duplicate your sequence, and then reconnect your raw media folder to the 29.97 folder, render, export, and see how it plays.
3. Broadcasters are getting more and more mixed video every day, so rather than converting from 24 to 29, see if they'll take just 24p. Or, what I've done in the past is, if they want 29.97, let their own techs fight this issue out. Send them the 24p master, let them convert it, or, beat themselves up over it, but in some cases, they may just take it in 24p.
4. Export your 24p sequence directly out of Premiere, at 29.97, see how it plays.
5. There are more expensive routes others have taken, involving taking it to a post production conversions house, where they do a more expensive and it's like a true frame-rate algorithm conversion or something that takes time and money. I heard about this problem on "Meet the Mormons" documentary, when they were using mixed footage and FCP7, and they ultimately had to do a "hardware frame-rate conversion", rather than a software-driven frame-rate conversion".
Sorry if none of this helps,
Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah
http://www.digitalchophouse.com
