In reading about the 3.13.1 update, I'm not really sure after reading it. At the top for 3.13.1 it says "This is a Japan only release. Release for the Glo and Aura H2O only. Touch, Mini and Aura are excluded." And then further it gives a link to download the firmware for "Mark 4 Hardware: Glo (+ Aura HD)."
I'd wait until someone else who knows what's up with that firmware posts. I haven't updated lately and still on 3.12.0 because it's been so perfect, no bugs that I've noticed. But I did turn on wifi to see what would sync, and what downloaded was 3.12.1. So 3.13.1 might really be only for Japan models?
Now to get my patches installed for a nothing update.