MSM not an expert on taxes but will try to answer this question (have fun with taxes in march

)
for a Canadian you pay taxes on dividends, however you are get a better tax rate on dividends (dividend tax credit).
As for US residents not sure how it would apply, however would assume you get most of the taxes back.
should say this can get complicated, because are you referring to a bank stock, pipeline (2-4% yield ) or an income trust which yields 8%-15%)
some of these income trusts are taxed differently, some business trusts the income is taxed as interest.
some are taxed as a Return of capital and can qualify as capital gains, and do not have to be paid until sold. on the ROC.
some have a mixture. would assume if you are a US citizen you would get most of the cdn. taxes back. however best to ask a tax expert (accontant ) or revenue Canada or the IRS could help you. also sometimes the company can answer this for you.
in the income trust in Canada many are businesses that operate in the US, I own DR.un (health care, rent medical facilities), IUR.un D.un mostly US real estate, BFI canada which now has most of its revenue coming from US garbage.
should note most blue chips cdn. companies can be bought on US exchanges except for the income trusts I listed. I sell my income trusts if they cut distributions.
thanks
selkirk