nokia2003,
Yes you right, after i updated carrier info in iTunes, I lost Cellular Data Network menu too (which previously i put random credential to stop iPhone from using 3G data), and now iPhone will automatically connect to 3G or Wap if there is no wifi available...

my phone bill is ticking up and i'm considering to take a data plan, either iValue 1 or add on unlimited 3G to my existing plan...