I was down in so. cal for winter training this weekend and my 10-speed dura-ace front derailler ceased to shift for no apparent reason in the middle of a training ride. It simply wouldn't budge out of the big ring.

Today I removed the derailler from the clamp ring and noticed that the tension spring was loose and there was no tension whatsoever. Turns out that one of the two metal sticks that protrude out of either end of the derailler coil had snapped out of place. It locks into a groove on the derailler body. Somehow, it had snapped out of place, leaving the spring uncoiled and loose and lacking in any tension at all.

With great force, I was able to push the spring back into alignment and the derailler now works, but I am concerned about that happening again. I didn't hit any major pot holes, and was not in a crash, so I don't know why that would happen. Has anyone else had trouble with this? Is this a common problem with the new DA front detaillers?