ok i spent hours upon hours researching this matter before calling Cingular. below is what i did and what you should do if you want to get the Internet configured correctly (so you can use 3rd party apps) and avoid the dreaded "could not open tunnel - failed" error message.......
btw - after performing the 4 steps below Verichat worked like a charm
#1 - call the (866) 490-2666
Blackberry support line - DO NOT CALL Cingular Care (they are clueless when it comes to Blackberry configuration/setup).
#2 - ask for the Blackberry (non-BES) plan you need (tiered/unlimited) AND ask that they specifically use one of the "new" plans. The newer plans are set to auto-provision your account to avoid all of the troubles of the past (got confirmation of this today).
UPDATE: my unlimited plan is BB UNL ADD ON - $44.99
#3 - configure your TCP option with the appropriate info - How to Configure Full Internet Access On BlackBerry
#4 - remove battery from your
, wait 30 seconds, reinsert - all is right with your Blackberry!!!