make JB native dialer use DATA for Google Voice OUTBOUND calls

[mixersoft]

I'm trying to do the following:

• use native android dialer (currently JB), and native Android SIP client for internet calling
• make OUTBOUND calls over DATA (TMobile prepaid) using "Call with Google Voice"
• have my Google Voice number show up as the caller ID

I currently have everything set up correctly to receive INBOUND internet calls with Google Voice+my callcentric DID. The calls show up as an "internet call" and I have confirmed on my TMobile account that I am not using any cellular minutes.

I can also use the Android Dialer to make OUTBOUND calls over SIP ("Call Without Google Voice"+"Internet Call") and not use any minutes.

But if I complete an outbound call from the native dialer using Google Voice I am always charged cellular minutes. This happens even though I set my Google Voice "This phone's number" to my Callcentric DID.

What am I doing wrong?