A frozen ATPL i believe is a pass in the theory exams, however the candidate does not yet have enough hours to hold the licence. Therefore the licence is "frozen" until you get the required time.
I too have a question regarding licencing in Canada. Are you able to fly in Canada on a US FAA ATPL or equivilent? Is there much involved converting from a JAR ATPL to a Canadian one?
Any help on this would be great, I'm down here in Oz so don't get to hear much about what is going on up there!