Well, after a MORE exhaustive search, I found most of my answer:
Originally Posted by cpx
Here is a note from the depertment of state (US)
http://travel.state.gov/travel/cis_p.../cis_1753.html
Most U.S. citizens, including dual nationals, must use a U.S. passport to enter and leave the United States. Dual nationals may also be required by the foreign country to use its passport to enter and leave that country.