I redirected a subdomain of mine to a new domain recently and it went without a hitch. No traffic lost. The new site seems to be doing fine. I don't even think I did the GWT change-of-address setting either. I have seen other sites pull it off too, based on their Alexa rankings. One day they were one domain, the next day they were a new one with no loss of traffic. I would be concerned that something was not implemented correctly with your strategy. Good luck!