99 windstar won't start without keyless

My windstar won't start unless you hit the unlock button twice on the keyless FOB. The local Ford dealer looked at me like I'm a moron when I asked him to disable it, and anywhere else I take it the seem surprised that this has to be done. The problem is that I am now down to one transmitter and don't want to spend the cost on the labor to program a new one. I've browsed the forums and I think I'm going to order my own transmitter and try to program it (tried to use the program instructions for my keys on my mustang and failed, but maybe this time will be better) but I would still like to disable this feature, I feel if someone steals one of my programmed keys, they have all my keys and will have the keyless anyway. Any help would be appreciated.