Originally Posted by hfly
1. Natural born US citizens make no such oath and make up far more a percentage of the population than naturalized citizens.
This has nothing to do with the OPs original question as s/he is not a "Natural born US citizen"
I am a natralized American born in Canada.
Originally Posted by hfly
2) Many countries do NOT allow their citizens to legally renounce their citizenship, so no matter what "oath" a person makes they are still considered a citizen of the original country.
Hence the OPs question (and a follow-up response shows that you can indeed renounce Canadian citizenship).
Originally Posted by hfly
3) As you have stated, no one actually asks for proof that ones original citizenship has been renounced, this is basically because of (2) posted above.
These are two seperate issues. One is how your country of origin treats you; the other is how the US treats you. Again, this has no bearing the OPs question.