We've had intermittent reception since the Montreal stations went digital last year. This is from a side lobe of an antenna in our attic pointed at Mt. Mansfield.
Knowing how much better the Canadian Olympics coverage is than that available on NBC, my wife and I put a second $30 Radio Shack antenna aimed at Montreal in the attic a few months ago. We now get 100% signal strength on Ch 2.1 (CBC French), 6.1 (CBC English) and 10.1 (French). 12.1 (CTV=Olympics) runs 50 - 80% but is always locked. 15.1 (Global) and 17.1 (French) are lockable about 50% of the time. We are enjoying watching the Olympics on 12.1 because almost all of the big events are carried live rather than NBC's practice of making one wait until 10:50PM to see the big contests.
One technical note. I always had almost 100% signal strength from Mt Mansfield. Now that I've added the "Montreal" antenna to the installation including a good signal combiner, my signal strength on all Burlington stations has dropped a bit and Ch 3.1 runs in the 40% range. I know that it's a multipath problem and have decided to live with it because I don't have room for a rotor in the attic.