Like the title said, when text are used along with some motion effects, sometimes it will look choppy? (Please give me a word for this) and leaves some short after images. To fix that, set the text background opacity to 2 or 1, I prefer 1. Then switch to text background rather than editor background or something else (this options is a drop down box above the text background opacity option which is usually closest to the top of the text input box). Either directly pick the color white, or pick a dominant color in the background (this can be done using the tint tool). The text should now look better when doing motion effects and the background should not / slightly be tinted.