Ah, make sure each image is 512x512 or 513x513, these are the only two sizes I know that work on FH.
'Tis also a good idea to double check the material file f'er any typos as well as checking the file names and types of each image. If the material file says "preset_#head.jpg" and the actual file is a .png, change the name in the material file to that.
Let me know if either of these fixes y'er issue. If not, if be happy to assist ye further.