AutoCAD Civil 3D :: Locked Layer Causes Contour Label

I'm working in 2011.  Just labeling some contours in a new drawing, using the 'Multiple' setting.  I found I could only draw one tangent of Contour Label Line.  If I continued, I could click but no labels were created and on finishing the command I could see that those clicks had been ignored.  What gives?

I found that the labels were on the current layer, instead of the layer they're meant to use.I also realised that my current layer was locked (from the previous task).

if the current layer is locked, the contour labels ignore the layer setting that they are meant to use, and come in on the current layer instead.  And you can only draw one tangent's worth of contour labels at a time before finishing the command and restarting.  

Solution: make a different layer current or unlock your layer.

are contour labels generally created on the current layer and then moved to their proper layer?Is that why it hit a snag: it wasn't permitted to move the object to a different layer because the one it was on was locked?