How does an American Pipeline MLP deal with the fact they have to pay Canadian Income taxes ? And how does it affect their shareholder's tax return, when the Limited Partnership is doing business in other countries ?
There has been discussion about this in the past on the Investor Village MLP board. Maybe you could find the relevant messages by google searching.
In past years, PAA unit holders had to file a Canadian tax return too (not good). Starting in 2011 (I think) the company did some kind of restructure whereby US holders no longer needed to file a Canadian return. Whether that changes again with new Canadian acquisitions is unclear.