I have a Vapolution, but it sounds like a similar idea- I have to put a small "plug" of weed into the glass end that is then put into the heater- the weed should nNOT be ground up, since it has to hold together. You don't want it loose, for as you have discovered, it falls out. Be careful not to pack it too tight either, as it needs to heat evenly. If your weed is a bit moist, it works better. I put a thin slice of lemon peel into my jar of weed to rehydrate if it gets too dry.
Hope that helps you!