Welcome!! Check out this post about setting up tanks. http://ball-pythons.net/forums/showt...-With-Pictures!
As others asked...what device are you using to measure humidity/temps?
your UTH would "help" more if it was under the tank. MAKE SURE IT IS ON A THERMOSTAT (this will regulate it or it will burn your snake).
Humidity wise, try setting his water dish closer to being underneath the heat lamp, cover 90% of the screen with foil or get sphagnum moss (found at pet store) and spray it down and set it in little disposable (Dixie) cups in his tank.