Marsye,
We have the exact same popper and have a newer microwave. DH said to tell you that it won't work if you use the popcorn setting on your microwave. What you have to do is set it for 2-1/2 to 3 minutes on full power. (He said something technical about the newer microwaves sensing the moisture and it doesn't work that way with the popper). ;-)
Hope this works for you.