Doublesided + margin

[AlterEgo Qasars <quasar@econ.muni.cz>]

Good evening!

I want to typeset something in doublesided layout. Moreover I have to 
typeset some stuff in margins---in the right one at odd pages and in the 
left one in the even pages. I have set ConTeXt in a following way:

\setuplayout
	[backspace=2cm, width=10cm, 
	leftmargin=0pt, leftmargindistance=0pt,
	rightmargin=3cm, rightmargindistance=5mm]
\setuppagenumbering[alternative=doublesided]
\starttext
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\input tufte\inmargin{\bf AAA}
\stoptext

At odd pages (1,3,5) everything is all right, but on even pages (2,4,6, 
...) the margin is placed in the text. What's wrong? How could I typeset 
it?

Many thanks,
Michal Kvasnicka