I'm working on a rather complex document containing frequent use of
positional graphics. Unfortunately, I've discovered what I expect will
be a pretty nasty problem to fix. When I combine horoffset,
startitemize, & positiongraphics the graphics are placed in the wrong
spot. I've managed to cook up the simple test case below which
demonstrates the problem.

===============
\setuplayout[ horoffset=.5cm ]
\setuppagenumbering[alternative=doublesided]
\setupcolors[state=start]

\defineoverlay [backgraphics] [\positionoverlay{backgraphics}]
\setupbackgrounds[page][background=backgraphics]
\newcounter\CurrentCallout
\startMPpositiongraphic{mypos:line}
  path p ; initialize_box(\MPpos{\MPvar{from}}) ;
  p := lrxy..urxy..ulxy..cycle ;
  p := center p shifted (-.5cm,0mm) -- center p ;
  pickup pencircle scaled 2pt ;
  drawarrow p withcolor red ;
  anchor_box(\MPanchor{\MPvar{from}}) ;
\stopMPpositiongraphic
\def\myitem%
{\doglobal\increment\CurrentCallout\item
 \hpos{myitem:b:\CurrentCallout}{\strut}
 \startpositionoverlay{backgraphics}
  \setMPpositiongraphic{myitem:b:\CurrentCallout}{mypos:line}
 \stoppositionoverlay}

\starttext
\startitemize[n,serried]
\dorecurse{30}{\myitem\input tufte }
\stopitemize
\stoptext
===============

-- 
Stuart Jansen <sjansen@gurulabs.com>
Guru Labs, L.C.