At the end of some instant movie themes there is a rolling credit such as in the Outdoor Adventure and Art-in-Motion themes. In a project where the frame rate is 29.97 fps, the rolling title appears as if it is being "grabbed" or "restrained" at regular intervals. This happens even in an exported movie. It's almost like the title is being played back at a different frame rate.
I found a way to correct this so the rolling title is silky smooth.
But first the instant movie has to be broken apart, after which the rolling title can be selected on the timeline. After selecting the title on the timeline, use the "Find in project" command to locate the title in the Project Assets. After selecting the title in the Project Assets, use the Export Title command and save the title using a different name. I just suffix the filename with a letter or number: Art-in-motion_HD_Credits_2.prtl. Next use the Replace Footage command to replace the original title with the title just saved. This updates the timeline with a rolling title that is adapted for 29.97 fps. After exporting the movie, play it back and notice the difference.