Addison: did you partition the card now? If you did, you're doing it wrong. You want to dump the contents of debian-m5-v3b-rootfs.tar.bz2 into your new partiton.

The v3c image file is 1.9 GB, you need at least 2 GB free in your FAT partiton if you're going to go that route. But if you have the dedicated partition, use that instead.