[NTG-context] \big\lfloor and \big\lceil do not work

Hi, This is based on another question on TeX.SX http://tex.stackexchange.com/q/242256/323 Minimal example: \starttext \startlines $\big\lfloor x \big\rfloor$ % No delimiters $\Big\lfloor x \Big\rfloor$ % No delimiters $\left\lfloor x \right\rfloor$ % Works \stoplines \stoptext Any idea what is happening? (This also fails with cambria, so something is wrong with the settings) On a related note, the following does not work either: \starttext $\left\langle x \right\rfloor$ \stoptext Not that one would ever use such a notation, but it is weird that it does not work. Aditya