I'm glad to hear that burning those stupid stinky leaf piles works to get rid of the bug but I've never really understood why they even need to get that way to begin with, I mean why don't EA just stop that from happening in the first place? It's currently Autumn where I live right now and I've never noticed leaves getting like that in real life.
I got that bug in a recent game but as it was a Tournament Challenge file for me, I just ignored them as I didn't want to waste time burning the stupid things, it was an eyesore however.