Hi,
I am not exactly sure why you flashed your VZW TP2 radio.
The radio itself is not locked, there is only a SIM lock and Verizon Global Support will gladly give you the code to unlock for free.
Nevertheless, AT&T appears to use a proxy for their internet services on their windows mobile phones. This is possibly why you cannot connect to the internet.
The following article is for the AT&T 8125, but since it's also Windows Mobile, it shouldn't be too different.
http://www.wireless.att.com/answer-c...tionId=KB56475
Be aware that according to several reports on this forum, the VZW TP2 is not capable of 3G bands that are used in the US. This means that if you do get it working, you will be limited to EDGE, which is relatively slow.
Hope this helps,
Nite Rider