CTD issue

Can anybody tell me whats causing this problem? Every so often, when I setup a flight I go to the fuel and payload menu and adjust my payload or fuel - vice versa either order, The second I click ok to adjust, It crashes to the desktop. Its happened to several of my aircraft. I dont know if thats a SIM issue or a aircraft issue, I've noticed it does do it more on aircraft with alot of payload stations, would that be dealing with the sim trying to calculate the CG after the adjustment? Or is there something else?