I've been trying to make a new sound font for my Nano Biscotte v4, and I followed the steps outlined in both the digital manual for the board and on the Plecter Labs page. I've managed to fully design and test out the font with the saber sound mixer provided by Plecter Labs, but plugging it into my saber sound board (and reformatting the SD card) gives an error sound when it is selected and will only play the power off sound. Any ideas what I may have missed/messed up?

P.S. I intend to upload the font so you can check my work, but apparently uploading it as an attachment won't work, so are there any suggestions there?