I unlocked my IP4 with jailbreakme.com a good few months ago now. I have ultrasnow on it..however, i dont think its working. When i insert the SIM it shows no bars of signal or says 'No Service'. At times when in switch it on or insert it i get a message reading INVALID SIM as a pop up. Ive tried the sim in a spare phone and it seems to work fine. So im guessing its not unlocked correctly? The other thing is i away from home for a few weeks and dont have my computer which i normally backup/sync my iPhone to so if i were to make a custom IPSW i will lose my music, apps etc?! Is that correct? Thanks in advance, really could do with using my other SIM!!!