A marriage valid where it takes place is valid in Canada, although the reverse is not always true (same-sex marriages are valid in Canada, but not so everywhere else).
Technically, your second "marriage" is really only a wedding ceremony (a renewal of vows, so to speak), because if you are already registered as married somewhere else, you cannot register your second ceremony as a "marriage" in the country where it takes place, it is a redundancy. Most countries require that before you get married there you legally declare that you are lawfully able to do so, and insofar as I know the law in Jamaica, I know that requires signing a form declaring you are not already married to anyone else someplace else. How it would work if you were marrying the same person again, I do not know, but I doubt they would register such a marriage and issue an official marriage certificate for it.
The conflict I see is the same "marriage" having two different certificates issued by two different countries at two different times. It just leaves a loophole for abuse. I can see where failing to declare that you have a legally subsisting marriage somewhere else (even if it is to the same person) constitutes a misrepresentation in the eyes of the law.
