On a Blackjack with Cingular Prepaid...

The "call" cost summary window pops up not only after a call but
whenever a data connection is closed.

I recall on my Nokia 6030 there was an option for me to choose to have
this window displayed at all but there's none on the BJ.

Anyone know of a registry tweak to handle this? I very much like the
call summary - especially with Cingular being known to make billing
errors - but it should only appear when a call is ended.