i am not that clued up about resistors and all that jazz
resistor = resistance to flow of electrons (current)
Globe = Resistance of flow of electrons (current) Where there is reistance the electrical energy changes from to heat and light energy, a globe.
So they both do the same thing, but a resistor is designed to slow the flow of electrons for use a b and c in electrical circuits. The resistance of your LED's is far less than the resistance of a globe. Which is the reason you changed (one way or another). The system you have most likely needs the resistance from the globe that was meant to run on the circuit. By replacing the globe with LED's the resistance drops, and the resistance needed by the circuit is no longer there. By putting in a resistor the system gets its resistance and thinks everything is fine. Take your globe down to an electrical store, dicksmith, jay car or something and say you need a resistor with the same resistance as this globe. They cheap as dirt and the person serving you will know exactly what your looking for. Then when you get home, cut the positive wire to the LED's and put in the resistor and all should be well. Not as tricky as it sounds.
If you dont wana get a resistor you just put the globe in like some1 else mentioned and just hide it somewhere, this will create the resistance needed for the system (if thats what the problem is)