If you are working through an agent for this show, all contacts 'should' be reffered back to the agent. That seems to be the proper thing to do.
Regarding the commission, there would be 2 points.
#1) You should of already had an agreed upon percentage for the agent when you signed with them. If not, pay the 25% and move to renogotiate the split between yourself and the agent if you think it is too high. Frankly, I think 25% is a large number. But you do need to consider the big picture. Does this agent get you alot of good paying work? If yes, pay it. If not, take this show and re-think this agent.
#2) Would you have had this corporate show 'without' this agent? It can be a great connection...
No matter how thin the pancake is, it still has 2 sides. www.JeffEzellMAGIC.com