I had the same problem on my 03, but never took it too seriously until I had to ride in the passenger seat and had to hold the seat belt out away from me to prevent being strangled. I thought the ratchet had corroded or something until I saw Eric's post.
Unfortunately I messed up! Since I accessed my seat tensioner from the front and saw a plastic cover I assume was the one to remove the child seat feature. It was the plastic section that contained the clock spring. When I removed it, it gave a nice whirl as it unwound. After several attempts, I was able to get the spring wound back up and back on.
After this, I went to the back side and found the child seat strangling feature and was able to pry it off and disablle it as Eric says. After everything was re-assembled it seemed to work fine.
Blake