Bruce,
If the trigger moves freely in the triggerplate when it's out of the stock, then the first thing I would suspect is the trigger slot in the wood. It could either be binding on the sides of the slot, or the top of the trigger bar could be catching in the top of the trigger slot. A little bit of inletting black on the trigger bar should show you where it is, then it's just a matter of removing the offending wood. Hope this helps.
Eric