Don't know if this helps, but I found if I have clip taken from a still image that pans/zooms, and I have variable frame rate in the export, the result is not smooth. Using a constant frame rate worked fine however.
It seems that every time I save my project, the outline I set on the text decreases by 1 till it gets down to 1. I verified this by looking at the . vpj file in Notepad++ before and after a save. The &outlinescale=3 I had on every text clip turned to &outlinescale=2. Anyone else notice this or have a solution?