so I bought a 7510 off ebay. It was just an impulse buy. I was just tired of looking at my i730.

I switched sim cards, and my address book didn't transfer. I can't even figure out how to send a text message. I had a friend send me a few texts, but I got nothing. I put the sim back in my i730 and I got my texts. Did I buy a crappy phone??? I need help here.

The BlackBerry does use the SIM card address book like the phones do. BUT, you can import the information from the SIM card into the BlackBerrys address book.

Open the Address Book on the BlackBerry. Press the scroll wheel and select SIM Phone Book. Press the scroll wheel after the address book loads and select Copy All To Address Book. All your contacts should now be in the BlackBerry address book now.

Wirelessly posted (Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0) BlackBerry7250/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/104)

And if you don't have a Blackberry Data plan from Nextel (not just regular data plan) your Blackberry will not work for anything other than phone and DC.

the 75xx series will not read any sim besides the white one.