The snow won't stop! AHHH!

Ok, I have this page I’m working on where there are numerous backrounds. You click the next button to change them. Anyway, on one of the backrounds is a winter theme, and I used the Falling Snow tutorial to make snow fall on that set of frames, but when you choose any other backround after that, the snow follows. I wan’t the snow to only fall on the winter backround.