1307 is the most recent stable bios
1403 is crap and was removed from Asus site...I have it linked in my sig for thoes who wish to try it ( I have had some requests so thats why its there )
I personally would would use 1307 its seems to be the best to date...1403 offerd nothing, pull-ins still do not work, same crappy tref value, and a nice port hang on boot up
One would think that a company like Asus could put alittle more effort in bios support for the ROG line of boards