There is a way to do this but you have to haave a little time on your hands.
Once you have your flattened timeline clip, do the following.
1- In Preditor load the flattened timeline clip and export the audio. (remember where you saved it.)
2- Go to Animator/Compositor and load the flattened timeline clip. Say yes for the extension of the time and set the save format (where it says still) to AVI, keep it as an uncompressed avi for better results. You will need to save to a drive that has a good amount of free space depending on the length of the clip. Now save it.
3- Once done you need to load the avi in your favorite avi editor and make some changes and additions to it.
The avi you now have is set to 60 fps. You need to bring it back to 30 fps.
The audio you extracted is set to 48 khz you need to convert it back to 44,1 khz.
From there you just need to merge the audio and video into one clip and then convert that to what ever format you need it to be for the DVD.