I'd forgotten another thing.
There's a creepy neighbour who spies on you and sometimes sends an email that he's spotted a rare collectible in the yard. That won't necessarily be a bug, though, it could be one of the leaves and nuts collection or a bone.
EDIT: Actually, I'm not sure if the first one I mentioned is in VF1; it might be only in VF2. The second is definitely in both games, though.