Instruments with Drumline converting to mp3

I have made several cadences with the added on marching percussion instruments and soundfonts. I want to download the mp3's of these cadences to my iPod so I can listen to them on the go and share them with my friends. When I downloaded the mp3 to iTunes though, the soundfonts for the drums were replaced with a piano soundfont. Is there any way to keep the marching percussion sound when converting a drumline piece to an audio file?