said by vp71inet:
The issue was mine. Because of some unknown calls on my other A/C, etc I had been proactive in restricting call features and had turned off international calling on the "Account Setting" --> "Account Restrictions" tab.
Also remember that both CallCentric and Voip.MS allow you to enable/disable calls on a country-by-country basis.
So you could (for example) allow US, Canada, UK, and iNum, while blocking other outbound calling.