Apropos... What about this?
Stephan Index: src/mathed/InsetMathHull.cpp =================================================================== --- src/mathed/InsetMathHull.cpp (Revision 34630) +++ src/mathed/InsetMathHull.cpp (Arbeitskopie) @@ -1469,7 +1469,7 @@ case LFUN_MATH_NUMBER_TOGGLE: // FIXME: what is the right test, this or the one of // LABEL_INSERT? - status.setEnabled(display()); + status.setEnabled(display() != Inline); status.setOnOff(numberedType()); return true;