The closer the iPhone gets to a full charge, the slower it goes for charging. At the last 5% it's almost a trickle charge. I tend to charge mine overnight if it starts getting too low. I always have a full charge in the morning. I also reset my usage before I undock, so I can track how much I am getting out of a full charge.
Have you run down the battery to where it says "please connect to power?"
One last thing to do before calling the dumb "tech support" at Apple (which got hired in a month) is to do a restore. If you still have issues after that, then go ahead and get a replacement.
Thank you guys. I will do what you suggested. if it still doesn't work I will drive a half hour to king of prussia and get it replaced. Screw mailing it in.