Smoking chicken with a water pan will almost always give you rubbery skin. Try a higher temperature, 225 to 235 degrees, with no water pan. Baste once or twice with oil or butter.
Alternatively (my prefered method), smoke it for an hour with medium smoke, then transfer to a preheated oven at 350 or 375 until done.
"Iím going to break one of the rules of the trade here. Iím going to tell you some of the secrets of improvisation. Just remember ó itís always a good idea to follow the directions exactly the first time you try a recipe. But from then on, youíre on your own." - James Beard