I have 6 WVC210's and they all exhibit the same issue.
When you pan all the way to one direction, the camera image dips and doesnt stay level.
Instead of the lens looking like this "-----|-----" across the pan, it dips down and to an angle and the lens doesnt level correctly all the way to the right or left.
I'm probably not explaining it right. I could post some photos to clear up any confusion.