Hi Patrick,

you are right. If I change the header text such that there is no 
underbar in there then the error disappears.

I prunned the example to investigate the situation further. Now I have 
only two pages. If you "texexec" the file then you get the error. If you 
uncomment the \page command at the end then the error disappears.

BUT NOW THE SITUATION REALLY BECOMES STRANGE!

If you delete all *.png files except the one that is included by the 
\externalfigure command then the error also disappears! It seems that 
the behaviour of Context is influenced by the content of the directory!


--Stefan