Did you ever find an answer as to why simply taking the camera apart and putting back together again fixed it? I had the same C31:42 code on my Handycam DCR TR7000. Before I searched the web, I took the camera appart to clean everything. It already looked clean as new but I cleaned it out anyway. I then put it back together and now it works fine. Cleaning it might have fixed it but I highly doubt it. I think there is something else. My guess is that something inside the camera was sticking. Taking the camera apart was enough to break this stuck part loose. That's my best guess. DeWayne