[NTG-context] checkbox in fields show the word yes

Hi all, with this example I get a checkbox that does not work; in my real world document it works, I can't say why. But this minimal example shows the problem I have in my real document. \usemodule[fields] \setupinteraction [state=start] \setupfield[cbox][width=1em,height=1em,option=printable,frame=on,offset=0.5mm,frameoffset=1mm,type=radio,color=black] \definefield[test][check][cbox][yes][no] \starttext \field[test] \space Do you see the word »yes«? \stoptext Unfortunately in Firefox and some other PDF Viewer there is the word "yes" written in the checkbox. This makes the form useless as people think the given option is set to yes by default. Can I avoid this somehow? TIA juh