Lisa, do you have hard water????? If so, get some Calgon (either powder or liquid) and use that in the wash to help strip it. It is on the laundry aisle.
I ordered a hard water testing kit for free from Culligan (one of hte great mama's here gave the link) and it showed my water is moderately hard. makes sense b/c I have shots on dishes, shower buildup, squeaky skin after showering, etc.
Good luck!