I'm not 100% sure, but I don't think you're supposed to load m8 raw. Here's how I did it:
If you want to be able to switch BIOSES by pressing diff buttons, you need the X-Chip BIOS anyway... load THAT raw.
Then after writing changes and stuff, (I'd recommend closing X-Control) reopen X-Control, read, then find a small bank (one that takes a quarter of a line). Right click it, hit load, choose your M8, right click on it again, assign it whatever button you want, then hit WRITE CHANGES in the menu.
Hope this helps.