Very odd. Is this ceramic, like a coffee mug? Or is it more like a refillable mug? If it is ceramic, it sounds like the manufacturer didn't glaze and fire it properly. Even a plastic type mug should have been better made. I would call Disney Merchandising, or even Conch Flats General store (The Disney World operator should be able to forward your call) and let them know you have an issue with the product, they may be able to replace or refund. It would be helpful to have the receipt, with the code numbers handy when you call, if possible. Good Luck...