[dcharlip]

Here's a registry tweek that works very well. It stops the data connection after 60 seconds (or what ever duration you desire).

To Stop Data Connection
go to : HKLM\Comm\ConnMgr\Planner\Settings
delete the "SuspendResume" line
add a new line called "SuspendResume"
select the type to be String
value of the key set to "GPRS_bye_if_device_off" (without quotes)
select key name CacheTime
change the key value to 60 (for 60 seconds before disconnect)