Originally Posted by LBPHeretic
It is probably not working because you are still on Android 1.5. Android 2.3 is required for SIP calling to work properly with your Google Voice telephone number.
I would recommend CyanogenMod 7.2 if you are looking for a good Android 2.3 ROM for the Sprint HTC Hero. Step on over to the root section if you have additional questions.
Oh, i updated to the current ota (i think it is 2.3). I cant get it to work on my evo 3d either.