After lots of trial and error I have found that my best connection is paying for the Total Unlimited Internet package and using "internet2.voicestream.com" server. I have tried all other options for my 1st Gen iPhone under all the data services and servers that T-mobile offers, and for my use and location I found that paying the $20 and having the Total Unlimited package works. However..
My problem occurs almost constantly, I always have Edge service(where available) and it works great when you first boot up my phone, but after a while I will get "Could not activate cellular data network." It just happens randomly. I will be on the network just fine and after letting the phone sit for a bit and going back to try and use any kind of internet related function it will give the error. I tried turning the Airplane mode on and off and it still wont get back on Edge until I actually reboot the phone. The "E" never goes away throughout all this. I have actually sat next to my sister while she uses her T-mobile Dash on the internet (also using internet2 APN) and watch her use the connection and look at my iPhone and it will give me error.
Any thoughts?
--should I be using one of the Cydia hacks on my phone even though I am using the legitimate service which I pay for?
BTW, I'm on 2.1 with Installer and Cydia installed. upgraded from 1.14 to 2.0.2 to 2.1 in steps, as they were released. (never had any issues while upgrading)