What format are you sending to the theatre? DCP? Blu-ray? Quicktime file?
Most film festivals require at least a DCP print and here's some info on that:
"If you want to make your life easy in post-production, always shoot and edit in 24p. 24p means 23.98fps (which is actually 23.976). DCPs actually run at 24.00 but the resampling between 23.98 and 24.00 can easily be done during DCP mastering. If you think you might eventually create a DCP (or even a 35mm filmout) from your motion picture, shoot and edit in 24p! A DCP is just like a 35mm print in that it runs at 24 frames per second. While there are other frame rates available, such as 25,30 and 48, they still are not in common use. The Academy and many foreign buyers and some festivals will only accept 24fps DCPs. If you have to shoot in traditional interlaced 60i (or PAL, SECAM or any other non-24p format), you should consider doing a frame rate conversion before you make a DCP. You can get good results if you have your footage professionally converted (or use good software such as Magic Bullet or DVFilm) from 60i or 25p to 24p. Unfortunately if you shot at 30p, the results will not look very good. Credit crawls and rolls in particular do not look very good when converted to 24p.
Sometimes, as with archival footage, you will not have a choice. If you have 60i archival footage (or PAL, SECAM, or any other type of non 24p material), it's best convert that as early as possible in the editing process.
In summary, edit in 24p whenever possible. Shoot in 24p if you can. NEVER SHOOT IN 30p. Convert any non-24p material to 24p as early in the editing process as possible so that you'll know what to expect."