Two identical BlackJack IIs, only one can maintain a data connection...

[Guest hellslave]

Here's the deal...

My phone fell out of my car and the LCD screen broke (it still has all functions, you just can't see a damn thing, so I use a Pocket Controller-esque program to view via the computer), so now I'm using my girl's old phone, which is also a BJII. Only difference, is I can't maintain a data connection with it for some reason (she has ALWAYS had this problem). On mine, I can, but not hers. I've compared all settings and they are identical to mine. But when I try to use the internet (I have unlimited data usage), I can't. This applies to IE, Skyfire (says "check flight mode"), Google Maps, checking e-mail, everything that uses the data connection. I can get it to work temporarily by sending a pic to myself via multimedia message, but that's it, and I have to do it every time if I want to use the internet.

I've performed all kinds of resets,from soft to hard, and I've also pulled the battery and SIM card for various amounts of time, yet nothing seems to make a difference. The promp I mentioned Skyfire giving me when it tries to establish a connection, leads me to believe that it has something to do with the phone's flight mode, yet I can find nothing regarding a flight mode in any of the phone's settings.

I've been searching everywhere I can think for help, but have no luck. Thus I turn you guys. Any help is much appreciated. Thanks in advance.