Stacka, that regulator works by shunting the excess voltage to ground. If the regulator wasn't seeing a good earth it would overheat causing it to fail. Could be the hidden culprit in a repeat failure. That's my bet, and it could begin at the connector.

A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)