help! frame rate issue with Motion

[Cynthia Granville]

hi all, i have been creating an animated logo for my company. i originally was working in 60i, then 30p because i was creating a lot of web content. now, however, for my narrative projects i'm working in 24p and that's the primary place i will use the logo. problem is, Motion will not let me save the project in 24p. i can click on that preset (HDV1080p24)in project properties, but then it changes itself to "custom" and i note that the frame rate is still listed as 29.97, with nothing allowing me to change it manually. i do not do a lot of work in Motion and lots of what i am very happy with was done more or less by trial and error, and the idea of creating this again from scratch to match the 30p project is extremely daunting...plus i fear this may come up again down the road if i'm using Motion for other things and i'd really like to understand how to get this to work properly. thank you for any help!