[NTG-context] Baffling error

I have a very simple file, with some 20 pages only and a few pictures, nothing extr5enuous, but when I include the following piece of code anywhere, it gives me TeX capacity exceeded, when producing a PDF file, that is, with "texexec --pdf book.tex" but NO error when producing a DVI file ... Can anyone shed some light onto it ? The piece of code is: \startitemize \item {\bf Low-strength concrete}: less than 20 MPa (3000 psi) \item {\bf Moderate-strength concrete}: 20 to 40 MPa (3000 to 6000 psi) \item {\bf High-strength concrete}: more than 40 MPa (6000 psi). \stopitemize The file can be found in: http;//math.berkeley.edu/~desouza/Context/ Paulo Ney