Which most recent cios works for dual-layers? Also I had rev 9 or 10 for a long time and my usb didn't work until I updated to rev 14 (rev 9/10 to rev 14)..... So I basically need to downgrade to a cios that supports dual layer games and my usb, thinking if anything it probably would be 13 or 12, but the search is weird now on this website, so I can't really tell. Also how do I downgrade to whatever cios I need? And which one do I need?