1999 OEM Keyless Entry Question

I have a 1999 with the factory keyless entry. When I bought the car, I was given the key and the keyless pad. This may sound dumb, but the key for the ignition does not seem to open the doors. This is not a problem now, but when the battery runs out on the pad, I will be in trouble. Isnt there supposed to be just one key for ingition and doors? Doesnt this sound weird?

anyone?

My 99 taurus's key works for the ignition and for the doors.

Did you buy it used?

try useing w-d40 it may loosen up the lock, if the lock has not been used for a while they tend to seize up a little w-d40 or graphite should do the trick. if not take it to a locksmith as it may be a different key.Good luck