Wirelessly posted (htc Pocket PC: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11) Sprint MP6950SP)
I would suggest you use a generic custom rom for your purposes and not a Verizon branded or shipped rom. You could always flash back to the shipped rom if you have to.
Regardless of the rom though, I think you are going to have to acquire, change and save settings in EPST for your carrier in order for things to work correctly.
Maybe if you put it in GSM only mode you could use some sort of over the air programming from your carrier to correctly program EPST.