I have a Nook HD that appears to only like the Barnes and Noble branded adapters. When I plug the nook into other 2.1a adapters and look at batter settings it says "discharging", when plugged into the Barnes and Noble adapter it says "charging". The other adapters I have tried all work find with my Mororala XYBoard tablet. As it clearly shows "discharging" I have not tried leaving it on the other adapter to see if it just takes a lot longer to charge, which it still should not as the power is higher.
Any one have any luck with other 3rd part solutions?