k i usually use cios36 rev10 i think it is and run my iso games off a hard drive and its been working fine and i find out ppl say to use cios38 rev 13a i think it is for ghostbusters and other new games that r gonna be coming out. well when i install cios38 rev 13a and boot up usb loader gx it tells me thers no usb device so i reinstall 36 rev10 and it starts working fine again and detects my hard drive. when i install 38 rev13a i use cios 249 i think it is to install it as its the first cios that shows so i thought thats what i was suppose to use. im on 4.0U if that changes anything hopefully someone can help me i kind of want to play ghostbusters but just mainly want to be using the best cios and be able to play the newer games that come out thanx and srry if this has been answered im a lil new lol.