I would not worry about it. Expedia sends reservations to the hotels by fax or email. The hotel then needs to manually enter the reservation, and then type in the confirmation number on their Expedia site. I know at my hotel, many many times the confirmation number gets entered incorrectly.

I would wait until December when they open, and call. Another thing, they may be using the old hotels reservation system, and not the Hyatt system.... Just for fun, try your confirmation number on the Dreams site.