[NTG-context] Strange reference (\in ...) problem

[Tobias Burnus]

Hello,

I have

\startcomponent foo
\placeformula[eq:bdy:elf:Csigma-def]
...
\informula[eq:bdy:elf:Csigma-def] % this works
\stopcomponent

\startcomponent bar
\informula[foobar]  % refers also to an eq. in 'foo' and works
\informula[eq:bdy:elf:Csigma-def] % this one does not
\stopcomponent

I defined 
   \def\informula[#1]{(\in[#1])}
in *.tuo I have
   \mainreference{}{eq:bdy:elf:Csigma-def}{1::0:2:3:1:0:0:0::17}{23}{2.22}
and in the log I get:
   references     : unknown reference [][q:bdy:elf:Csigma-def]

This is with ConTeXt ver: 2004.1.2 and also with ver: 2004.1.13.

Any ideas?

Tobias