I got two rooms in November of 03 for my parents and my brother's family to facilitate their visit to the space center after our family cruise. They thought the place was disgusting. The first set of rooms they were given, the front door was broken and both were overwhelmingly musty and mildewed. The next rooms were still smelly and less than clean, and in one the bathroom toilet kept malfunctioning. In hindsight, my Dad wished they had just walked away on the pre-paid and found something else.
The hotel was not busy and they definitely felt that they were being shown only the less desirable rooms because they were priceline. I forwarded a complaint to priceline but never had a response.
My best advice, if the room is not acceptable, complain and if the substitute is not acceptable, complain and keep it up until you get a clean, functioning room.