Yea, I've had one or two people bring up that issue to me in the past. Downloading Denny's map pack should fix the problem. In retrospect, I would guess that this problem came from me using some of her slightly modified models/textures in my work, since we're on the same server. There's a tree she used in one of those maps that's identical to one of Gravity's models, and must've accidentally used that one instead.
I don't mind if people make their own minimaps, or modify/fix the maps I put out! Go for it.