A big complaint that I always see on reviews is a musty smell when they enter the room at the resort. Most of the time there will be that musty smell because of the air conditioning. One great tip we learned from Kathleen & Nancy (Royal Hideaway Ensenachos) is to turn on the ceiling fan (provided you have one in your room). This will circulate the air and hopefully remove the smell.
Other ways to banish the musty smell is to light a scented candle or febreeze your room (yes, I actually pack these with me).