Just a thought from a fellow new owner. My sons snake which is just over a year (hatch date 2/7/12) is 475gr. Looks healthy to me. We have had him about three weeks. Fed him a live feeder mouse the first time no problem. Last week I bought a small frozen rat about 50 gr. I tried to lift his hide and do the dance and all that to no avail. He would check it out then move on to something else. Ended up leaving the rat in his cage turned out the light and left him alone. Came back an hour later and he was in his hide with the rat half way down. IMO i think some snakes need some privacy. Let it in there overnight and see what happens. No harm in that.
gdlk