Do you mind copying and pasting your preset's code (the contents of the .material file) here for us to look at?
If you haven't opened your .material file, right click it and select "Open With..." then select "Notepad". Whatever is in there, copy it all and paste it into forums using this
[code]paste entire code here[/code]
It's likely that it's an error in the code or that your file names aren't correct in each of the .material slots.