revision and bios

[iakoboss7]

well i tried the r-2540 (ok i know its not suported just curious) i have a bios 2:00 eu from my ps2 and a 2:20 us from my friend. when i use mine it goes in the memcards and is showing a cd and when u press it it goes back there again and again but in the us is works just fine (i know i can use the bios hack.....) i just dont get what's happening there. my emu works fine i played lots of games just that minor thing.