I dug out my old A320 today for a laugh as I got a 32GB Sandisk Ultra Micro SD off Amazon. I have a mini SD adapter but no matter which way in Ubuntu I formatted the micro SD I kept getting the kernel panic error. I tried Gparted, the Disks app and the terminal to no avail.
I had to get on a Windows machine and use the HP USB Formatting Tool that I saw recommended here.
I just found it funny that I couldn't get Dingux working with the formatting tools on a Linux machine. If anyone knows a way to do it properly in Ubuntu I would be most grateful to save me from M$.