Having problem with voxel replacement

[Carville97]

I wanted to create a new unit, and I did. I used a custom voxel and put the unit in the game. I didn't like the artwork I had done, so I edited it, and tried to put the new version in the game. Strangely, the old artwork would not go away, and I can't figure out how to make the game recognize the new artwork. I deleted every file with the old artwork, and the new artwork even appears in the Final Alert 2 editor, but the game still displays the old artwork that I want to get rid of. I'm confused, since I'm assuming the game needs the expandxx.mix file that I created to have the artwork, and there is no file with the old artwork on it. How can I make the game register the new artwork?