Trav, its not always easy to tell why or why not--beaver are not moving.
On your dam crossover--was the catch made on the bottom side of the crossover or the top? Also how far from the dam is the lodge or den? Is the dam ,the only dam? or is it one in a series of dams? If it is one of a series of dams,is it the first or main dam.or is it one further down stream?
Last but not least-- how much open water do you now have?
All these things can affect how often a beaver enters into a certain area,once you give me more info, we wil go on from there.
Also do you check your traps every day?
Tom