The game requires 4.31 firmware

Hey I just recently JB my PS3 with Rogero 4.30 v2.05 and tried to play Alien Colonial Marines on Multiman and said it requires 4.31 firmware, Do you want to change it to your current 4.30? What does this do? I'm scared it will update to 4.31 OFW. If I press no it goes to XBL and when I try run it I get the error. So should I do it?

Thanks