Cylinder Lock!?
 

Just bought my DVX100. 30 minutes after using it the first time, I ejected the tape (MQ), and some of the tape was slightly pulled out of the cassette. I wound it back in, put it back in the camera, rewound the tape, and the "Auto Off" "Cylinder Lock" Error message appeared. Then I turned the camera back on, it played and rewound fine, with no problems. I have not done any subsequent testing with another tape - which is my next step.

Any thoughts would be greatly appreciated.

could just be a defective tape

Wish it was just the tape. It's a serious problem with the cylinder. Last night I tested the camera with a few tapes and the same thing happened continuously. I needed a new camera. The place I bought it from happily gave me a new one.

I had to send my camera in today... it was "eating tapes" and displaying error messages like "auto off T reel lock" or "auto off S reel lock" or "CYLINDER LOCK" and when I called Panasonic Tech help they referred me to the Chicago repair center (the only DVX service site 1-847-468-5270) they said that it was not normal and to send in the camera. Luckily Digital Megastore (Jim ext 758) agreed to exchange it for a new one.
THe Panasonic tech Dennis Huntowski said that I should be using Panasonic MQ tapes because the dry lube didn't cause problems. (I was using Panasonic AY-DVM60EJ that I got with the camera)
My usual source Edgewise Media (Colleen Leary)
http://www.edgewise-media.com/panmindv60mi4.html
Has a better price on MQ than tape resources by a little bit.