cingular network help

[projectpaki]

ive had this problem where when im on the phone with somebody the phone goes silent suddenly. the call has ended but the phone makes it seem like it hasnt and the timer keeps running but it wont let me end it.

i found out the problem was when the network was switching from 3G to G, when it would switch the call would disconnect. so as of recent ive chosen the network to stay at GSM (losing all 3G advantages), and i havent had this problem since. should i keep it at GSM, or change the network to WCDMA? for cingular, what would be better? advantages? disadvantages anyone?

thanks.