I experienced a similar situation with zero availability showing up on HHonors and through the hotel directly. Hotels. com showed availability so I booked through them. I knew that the stay would not be eligible for HHonors points, but called customer service anyway, and was told that they would contact the hotel and make an exception this one time. My staye was credited for the full point value shortly after my stay. This happened about two years ago so they may be less forging now.