I am having the same problem. I spoke with a CSR and she told me there is limited availability for flights using RR1.0 rewards. I asked her if the blackout dates had changed and she said no. She told me that all the reward flights were already booked for that date. I tried to book on the release date for a flight in October so I find that suspect that all the flights could already be gone. It appears that they have limited the flights you can book with an old reward.