x2 to what the others said about the UTH.

3 lamps? That does sound quite excessive. What are you using to measure your temperature and humidity? Use digital. Analogue is worthless.

Also: I have had many, MANY troubles with humidity myself (and that was just with one lamp) and since I'm not going to upgrade my tank anytime soon, I suggest you find the sticky on putting foil on the cage. It does wonders.

And your aspen bedding IS suppose to help with humidity; you can spray until moistened but not soaked...but with 3 heat lamps I doubt it will stay moist for long.