Duplicate label warning

Hi

I am making a cartoon and gave some frames, labels. For instance I have a keyframe with a mouth that says “ee”, “o”, “a” etc, and label on those keyframes so I easily can identify what keyframe contains what.

My problem is that when I compile that movie, it says:
"WARNING: Duplicate label, Symbol = <symbolname>, Layer = <layername>, Frame = <framenumber>, Label = <labelname>

How do I solve that problem? There is a white pop up coming up with those lines every time I compile the whole flash…

-Aleq