I have had the same planner for about 3 months now, bought it the same
way, infeed/outfeed tables, dust bag, and stand. It has been dead on
since I took it out of the box. Beats my old Delta 12" by a long shot.
I have run, pine, walnut and a ton of 12" wide 5/4 oak without any
noticeable snipe. For long stock (6 to 8 feet) I will put a roller
stand on either end to ensure consistancy. Have you called Dewalt
yet? I had to call them about a bad fence on my TS and they were great
about getting the issue resolved. They may even have an area rep that
could look at it.
-Marcus