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Wirelessly posted (BB 8900: BlackBerry8900/4.6.1.250 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/301)

Do a software unlock, and it should work fine. Keep in mind you get no minutes with the $1/day prepaid plan. As far as getting internet working, these are tmobiles apn's, usually the sidekick apn or g1 apn will work with the prepaid sim:



Access Points Names (APNs)

T-Mobile Internet: Internet2.voicestream.com

T-Mobile Internet VPN: Internet3.voicestream.com

Web2Go/t-zones: wap.voicestream.com

BlackBerry: blackberry.net

Sidekick: hiptop.t-mobile.com

T-Mobile G1: epc.t-mobile.com
 
Wirelessly posted (BB 8900: BlackBerry8900/4.6.1.250 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/301)

Do a software unlock, and it should work fine. Keep in mind you get no minutes with the $1/day prepaid plan. As far as getting internet working, these are tmobiles apn's, usually the sidekick apn or g1 apn will work with the prepaid sim:



Access Points Names (APNs)

T-Mobile Internet: Internet2.voicestream.com

T-Mobile Internet VPN: Internet3.voicestream.com

Web2Go/t-zones: wap.voicestream.com

BlackBerry: blackberry.net

Sidekick: hiptop.t-mobile.com

T-Mobile G1: epc.t-mobile.com

When I unlocked my phone with ultrasn0w, the APNs weren't even necessary anymore. So, I have the T-Mo Prepaid sidekick internet data plan and I just popped in my SIM unlocked, and internet and txts went in and out just fine. APNs only mattered when using a piggyback sim like turbosim to keep the phone unlocked.
 
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