I just switched from my iPhone 3GS to an unlocked T-Mobile 9700. The iPhone sim card was moved over and the Blackberry Personal Plan was added. Everything seems to work fine (emails, browsing, etc), but the display show I am on EDGE, and never on 3G. The network preference is set for 3G/2G. Any advice on what I can do to get 3G working.

Thanks

You cant.
T-mobile 3G is a different frequency than ATT 3G, therefore you will not get 3G on ATT witha t-mobile 9700.

Yep - they are on complete different network frequencies and you can't get a T-Mobile 9700 to get 3G on AT&T (or vice versa).

Wirelessly posted (White and Nerdy)

Mhm. The EDGE and GSM will still work however. T-mo decided to go with a different freq for their 3g as the above said

I've used an AT&T and a T-mobile 9700 on their respective 3G networks and they are both painfully slow and not much faster than EDGE in my opinion. In addition, I've noticed a lot of dropped calls on both 3G networks. My T-mobile 9700 would reboot constantly on its own while in 3G and AT&T 3G is not all it cracked up to be. I don't think the 9700 is very good on 3G in general. I've actually switched off the 3G network in mobile settings and the phone is more stable and performs better. Perhaps as 3G becomes more prevalent there will be noticeable performance gains but for now they are miniscule if at all. I think the AT&T 9700 is a better performing phone and it can be used on all 3G networks around the world except USA T-mobile and UMA can be configured on it for use on T-mobile. Overall, I'm very happy running my unlocked AT&T 9700 on EDGE on T-mobile USA and having UMA available.

Incoherent.

You can configure an AT&T 9700 to use UMA on T-Mobile?

Please tell us how!

Incoherent? I did it in five minutes from the engineering screen. I had to do a little homework before but I got it up and it works flawlessly. Once UMA is enabled in the engineering screen the "Wi-Fi preferred" connection preference option will appear in the mobile network options. If anyone has an unlocked AT&T they want to enable UMA on for USA T-mobile, let me know and I'll help you out.

So share already. Inquiring minds want to know (and some of us want to giggle)

Sell the T-Mo phone on eBay and buy an AT&T version. It's the ONLY way.