I had the same experience. I simply did not select a seat and called the 1K line. My guess is the problem will go away assuming IT continues to fix problems with the site.

On a different note, I was trying to book a multi-city set of flights and the new web site refused to show availability in premium classes between Boston and SFO. I could see the fights on a simple RT and if I went to the old site (using a different browser where I'm willing to clear its history/cache) I could see the exact flights that I wanted to book. In this multi-city trip I decided to book the last segment in coach because the first class seat changed the fare from $2,600 to $6,000 despite the last segment showing a cost of $75. I ended up calling reservations and they could only see the $6,000 fare for the selected flights. I then asked them to do the booking using booking code which included a "G" fare for the final segment. This brought the fare down to $2,600 and the agent was able to book the flight