[racket] Can't scribble BNF grammar to pdf

I tried to compile the example from
http://docs.racket-lang.org/scribble/bnf.html
but it seems that pdflatex gets stuck when trying to generate the pdf.

I tried to compile first to latex code, and then directly use pdflatex and
I get the same situation.

I am unsure whether it is an scribble issue, or an issue with my latex
setup. I attach a minimal example file. I can compile it without problems
to HTML.

Thanks
-- 
Ismael
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20130905/1510a774/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bnf.scrbl
Type: application/octet-stream
Size: 662 bytes
Desc: not available
URL: <http://lists.racket-lang.org/users/archive/attachments/20130905/1510a774/attachment-0001.obj>