Filing 1040: What is special about Canadian tax treaty?

[tvinar]

I have two questions:

a) I was just curious which formulation in the article xxv of the Canadian tax treaty allows Canadians to fill 1040 instead of 1040NR, compared to other tax treaties. Or is this available for all tax treaties that show a non-discrimination clause?

For example, Slovakia-US tax treaty states:
"Nationals of a Contracting State shall not be subjected in the other Contracting State to any taxation or any requirement connected therewith which is other or more burdensome than the taxation and connected requirements to which nationals of that other State in the same circumstances are or may be subjected. This provision shall apply to persons who are not residents of one or both of the Contracting States. However, for the purposes of United States taxation, United States nationals who are subject to tax on a worldwide basis are not in the same circumstances as Slovak nationals who are not residents of the United States."

Is this sufficient to be able to claim the same benefit for Slovak citizens?

b) I am a Canadian and will be moving from US to a third country soon. Can I choose to claim this benefit even after I become tax resident of that other country (i.e., will I be able to file 1040 instead of 1040NR for 2007?)

[nelsona]

The treaty wording for Canada is changing to "nationals" as well , I believe, so residence won't be a factor.