PJC,
Yep, you are right, the crystals have to match. Since they are on different frequencies the radio will not work. That is why your heli won't work. If this is a new radio then contact whoever you bought it from and let them know that they receiver and transmitter are on different frequencies. Or if you want to correct the situation yourself, then purchase a new receiver crystal and change it out. You have to change the receiver because it's illegal in the US to change the transmitter frequency yourself. If you want to change the frequency on the transmitter it has to be sent in to an authorized repair shop.

Hope this helps

Ken