incrementnumber of part vs. not showing up in table of contents

["Mark A. Lilly" <misc@tinorb.com>]

Hi,
When i \setuphead[part][incrementnumber=no] so that all the chapter 
numbering will be continuous, the part doesn't show up in my Table of 
Contents. when i change it to 'yes' or remove incrementnumber, the part 
shows up in the ToC, but the chapters are now reset to 1 at each part break.

I want to have the parts show up in the ToC, but not have chapter numbers 
reset to 1 at each part.

%%%%%%%%sample, change incrementnumber=yes | no
\setuphead[part]
[incrementnumber=no]

\setuphead
[chapter]
[number=yes]

\placecontent

\starttext

\part{one}
\chapter{c1}
\input tufte
\chapter{c2}
\input tufte
\part{two}
\chapter{c3}
\input tufte

\stoptext
%%%%%%%end test


thanks,
mark

ps - is there a difference for this list between using \input tufte and 
\input knuth?