MDC-1200 signaling question

I am having trouble with making a VX-451 respond (in OFF-duty mode) to open it's squelch window to further accept any other signals, albeit, audio or DTMF. I have created the necessary contact list ID's with alpha tags. The VX-451 transmits it's own ID fine, but will refuse to open it's squelch when receiving a SelCall from any other radio within it's group. I am not sure what I am missing here, as the Help files for ANY of the new eVerge radios are quite cryptic and vague.

MDC-1200 signaling question