First I bought a new router, a Buffalo WHR-HP-G54.
Then I installed
dd-wrt on it and
did a bunch of bandwidth tests.
Those two steps are optional. Only do those if you're a hopeless geek with too much time on your hands. It's cheaper (in money and time) to get the T-Mobile router, use your existing router (which is probably fine
given this poll) or simply do your testing at Starbucks.
Then I wiped the blackberry (Options -> Security -> General -> Menu -> Wipe, make sure you have a backup first). I did not immediately connect to my PC to activate my BES connection.
Then I noticed that wifi was working perfectly. And UMA too. Whoa.
Then I hooked to my PC and activated with BES. An hour later I had all my data back and e-mail was working. But wifi and UMA were hosed again.
Then I noticed that my APN was not configured. Went to Options -> Advanced -> TCP and put in "wap.voicestream.com". Pulled the battery. UMA started working.
Then I noticed that wifi wasn't working perfectly. Once I
learned how to configure my browser and force it to go over wifi instead of routing my web traffic through my company's BES server, things got much better, and as of last night I am a very happy camper.
...but this whole troubleshooting path only works for my specific symptoms, which
I've listed elsewhere. What problems are you having?