Are you using the ArtRage Starter Edition or the ArtRage Studio Pro demo?
Is the stroke always displaced in the same direction from the point where the cursor is or something else? Also, can you let us know roughly how far it is displaced from the cursor? What is the model of your Wacom tablet? e.g. Bamboo Fun.
Expected behavior is that during the stroke, the stroke will be a little behind the cursor, then complete when you lift your stylus as we're using a rendered stroke rather than a dab based painting engine which allows us to do the paint and canvas interaction the way we do. The result should be that your stroke starts and ends where you started and ended it however, so if you're seeing anything different, let us know.
Resident Bug-Hunter and Support Guy