After fucking around with the Panasonic SD formatter tool for hours, doing a total of three full formats, I had enough, and booted my GNU/Linux PC.
To anyone else having this problem:Create a partition!
After formatting through this SD formatter, or via the Windows built-in utility, you literally have no partitions on your SD card. By running fdisk and creating a primary partition as W95 FAT32, then mkfs -t vfat /dev/sdb1 (replace sdb1 with your sd-card) my card now works perfectly with Dingux.
Thanks for the help, eule and yoshi41.
If anyone cares, this will mount mmcblk0p1 instead of mmcblk0, I'll let you figure out why for yourself