[NTG-context] \doteq math symbol is hidden in standalone minimals

Hello all, What is the problem when \doteq math symbol is hidden in standalone ConTeXt (minimals) - latest version? I suppose that is a problem in mathematical font. Can this be solved? In ConTeXt MKIV TL2011 everything runs normally. Here is my example: \starttext \startformula Hv \doteq 0,102 \cdot \frac{2 \cdot F \cdot \sin\frac{θ}{2}}{d^2} \doteq 0,1891 \cdot \frac{F}{d^2} \stopformula \stoptext Thanx Jaroslav Hajtmar