I made three planar surfaces. One I made with the polygon tool and the other two were freeform closed blobs. I exported as ai, and even though I had several programs that could pull it up so they 'looked' right I noticed that the only surface that could be filled was the one made with the polygon tool. The others looked right, but could not be filled. I have a hunch they would have to be traced first. Here is an ugly results picture.