definehead and section=

[Patrick Gundlach <gundlach@irb.cs.uni-dortmund.de>]

Hi,
once again, a (probably simple) thing I don't know how to do:

the file is:
--------------
\definehead[teil][section=section-1]
\setuphead[teil][head=nomarking,style=\tfc] 
\starttext
\teil{one}
\input tufte
\stoptext
--------------

and it gives me an error:

[...]
This is pdfeTeX, Version 3.14159-14h-released-20010417-2.1 (Web2C 7.3.3.1)
entering extended mode
(./defhead.tex{/app/unido-inf/sun4_56/tetex/1.0.7/share/texmf/pdftex/config/pdf
tex.cfg}

ConTeXt  ver: 2001.7.11  fmt: 2001.7.16  int: english  mes: english

[...]

system         : mark teil defined [teil]
system         : mark teilnumber defined [teilnumber]
systems        : begin file defhead at line 3
! Missing number, treated as zero.
<to be read again> 
                   }
\plaatskopnormaal ...}\hskip \numberheaddistance }
                                                  \vbox {\localkopsetup \han...

\doplaatskopnummertekst ...onhead \endgraf \fi }}}
                                                  }\endheadplacement {#1}{#5}
\dodododosomekop ...mmer ]{\finalsectionnumber }}}
                                                  \writesection {#1}{#4}{#5}...
l.4 \teil{one}

? x  

what am I doing wrong? Do I understand something wrong? 
Even with a self-defined sectiontype it is the same error:

\definesection[mysec]
\setupsection[mysec]
 [conversion=Character,
  previousnumber=no]
\definehead[teil][section=mysec]

Viele Grüße,

  Patrick Gundlach

- I TeX, therefore I am -