Well, this one is pretty foggy, which is why I missed the first time around and then had to break open my grammar book.Strange...I called my brother, who is an English major, and he said it was a gerund too, but he can't explain why. This is truly an odd topic. I hate things that can't be explained...
I think the bottom line is that the phrase does not function as the subject, object, or an object of a preposition.