If he's from a pet store, you should take him to the vet and make sure he hasn't got parasites, they could be the reason. Or maybe you could make the warm side just a little warmer, I keep mine at around 95. You could also put in a few more hides, one isn't enough. Maybe when he was digesting he didn't want to move from his one hide when he would have needed a lower temp? The analog thermometers aren't very accurate, make sure the temps are right with the digital (move it around the tank, or just get another one, maybe the Wal Mart one that everybody's recommending, with a probe and a humidity measurer as well). And measure the temp just on top of the substrate, that's where your snake's lying anyway. If I understood correctly, you're not using the heat pad? You should, because your snake will definitely prefer belly heat to bulb heat. Hope things work out!