What is your original source footage?: What model of camcorder did it come from and what is the video's format and resolution?
If you select Project Settings under your project's Edit menu, what settings are listed on its General page?
The source is an edited video - an MOV file.
There is an MP4 version, but it also doesn't play smooth when burned to DVD
The video is 1920 X 1080 at 23 fps
Editing Mode: DSLR
Frame Size: 1920 X 1080
Pixel Aspect Ratio: Square Pixels (1.0)
Fields: No Fields (Progressive Scan)
Display Format: 24 fps Timecode
There is no line on top of the time line when added to the project.
My computer has:
Intel core i7-6700 CPU 3.42 GHz
8 GB Ram
64 bit OS
Based on the information you've provided, I don't know why you're getting the problems you're getting.
Thanks for the replies, it's one of those mysteries...