Why does Joe Webb have WR elgibility?

My Yahoo fantasy football league has Joe Webb with WR elgibility. How does that happen?? The other team that I was playing(in the championship) started Webb(at WR) and I lost by 3 points. And if he had not used Webb I would had won by 9 points because his best reciever on bench was Maclin(with 7 points). ESPN, CBS, NFL, and ALL other fantasy leagues have Webb elgible at only QB. I am so upset at yahoo for costing me the championship game. I am never doing a fantasy league on yahoo again.