I had a similar issue. I used my main Mastercard, my (Canadian issued) Capital One travel MC and got the same result as you. Tried it several times and it would go to the "verifying" stage but eventually would come back that the charge was declined by my card issuer. This made no sense as I have a $20k limit with no balance on the card. I used another card, a Visa, and it went through without issue.
I called Capital One afterwards to see what had happened. They said they could see the request for the charges where I attempted it, but there were "communications errors" between them and Orbitz. Very strange. That's as specific as they got, which really didn't help at all. The odd thing was, I also booked my airfare through orbitz for the same trip, at the same time, and it went through fine. The only thing I can figure is the hotels came up on my statement as being charged by "Orbitz" whereas the airfare was charged directly by Air Canada. Not sure why that would make a difference, but it's the only thing that seems to be different about the charges (aside from the amounts).