hi folks...
sorry...i'm kinda new when it comes to 3GS...based on what i read... i think it's a big no no to upgrade to 3.1.3...

here's my problem... my aunt is using iphone 3GS...and maxis has been charging her GPRS charges which amounts to hundreds of dollars... she's kinda pissed with that but not sure how to fix it...i thought the only way is to try jailbreak and use SBsetting or bosspref to disable those edge and GPRS stuff... but then...she's a novice user and accidentally upgrade to 3.1.3 as well....

i'm not sure about those custom firmware thing... but my aunt's phone is officially bought from Maxis and is already unlocked...so is it still possible to jailbreak it since it's officially unlock? i only wanna get the cydia installed...and get those bosspref application...

thanks in advance....