I also get these "is not the power of two" errors all the time, although the pictures are all 400 x 400 pixels, what's the reason?
Try 512*512 (or 256*256) pictures instead, at a guess. I haven't used the object myself, or looked at your patch, maybe this will fix any other problems you have, or maybe I've got the wrong end of the stick completely.
Good luck, any way.