Okay. If he hasn't MADE them, then Wen, I think you should check for every file required by a custom component. These should be:
-a .gmf file
-a .txt file
-a .bmp containing the texture
-a .bmp containing the preview image.
If any of these are missing, that'll be your issue.
If they're all there, then I'm guessing there's something missing/mispelt within either the .gmf file, or the .txt file itself.
If you believe that to be the issue, leave a download link to the two files, and I'll take a look.