I'm trying play with the statistical package** for metapost from Anthony Phan. I found this strange problem:


This code runs fine:

\startMPcode
label.bot(btex Metapost and Statistics etex,(5mm,0)) ;
\stopMPcode

Also, this code run fine:

\startMPcode
input mps-core.mp;
draw fullcircle scaled 1cm ;
\stopMPcode

But this don't run!!

\startMPcode
input mps-core.mp
label.bot(btex  Metapost and Statistics etex,(5mm,0)) ;
\stopMPcode

What can coming from the module "mps-core.mp" that interfere with Metapost labels?

Thanks in advance

Jorge 

 **(www-math.univ-poitiers.fr/~phan/downloads/metapost/) .