As a biracial Montrealer who lived in Mtl for the first 20 years of my life, then near Toronto for the next 10, then back to Mtl, I have read this thread with interest.
There are many, many interracial couples in Montreal and I totally agree that there is political and linguistic history that impacts white francophone attitudes towards "others," who include English speakers regardless of race or family history (ie. many English Montrealers' families have been here for generations). And there seems to be some "fetishization" of black women, also rooted in history, IMO. I sometimes think it's more of a linguisitic issue than a racial one, it seems more important to be French than to be white. Again, IMO. I have a french last name (and a french family on one side that have been here for many generations) so I had a greater measure of acceptance. DH is white (not French), we never had a problem in Mtl. regarding our relationship. I haven't seen the kind or racism I have heard about in the States.
However, having spent a great deal of time in Toronto, the big difference I have noticed between Mtl and TO is that in TO, there is more real integration of newcomers and all races. You hear accents and see ppl of every colour in every facet of life. In Montreal, a certain amount of the population wants (and the laws enforce) people to be French, yet there is still racial/linguisitic/cultural segregation in work opportunities, etc. White, French people still represent the 'norm' whereas in Toronto there is a real sense of acceptance of everyone as Torontonians. I really loved that.
DH lived his whole life in Montreal and still would get passed up for jobs because he has an Anglo name. It's race AND language there. So when you get a bad attitude in Montreal, it may very well be the fact that you're english more than your colour or race. Ok, rant over.