[NTG-context] margin notes in MKIV (doublesided pages)

I need margin notes in a doublesided page environment in MKIV. The following: \setuppagenumbering[alternative=doublesided] \setupinmargin[location=both] \starttext \inmargin{n1}\input knuth\inmargin{note 1} \page \inmargin{n2}\input knuth\inmargin{note 2} \page \inmargin{n3}\input knuth\inmargin{note 4} \stoptext works in MKII. In MKIV, however, all the margin notes are on the left. So how can I get this right in MKIV? Alan