mpost not working

[Alejandro Aragon]

Hello everyone,

I'm trying to use the mpost command to create some pictures but it's  
giving me this message:

aaragon@~/Desktop/TeX/trunk/gnuplot/inclusion$mpost mismatch0.0001.mp
This is MetaPost, Version 0.993 (Web2C 7.5.6)
(Fatal mem file error; I'm stymied)

I heard somewhere that this program depends on the tetex installation,  
but I'm not sure. I tried to install it but when activating it I get

aaragon@~/Desktop/gfem TeX/trunk/gnuplot/inclusion$sudo port install  
tetex
--->  Activating teTeX 3.0_5
Error: Target org.macports.activate returned: Image error: /opt/local/ 
bin/a2ping is being used by the active texlive_base port.  Please  
deactivate this port first, or use the -f flag to force the activation.
Error: Status 1 encountered during processing.

I'm not sure whether the mpost is part of the teTex distribution or  
not. Does anyone knows how to solve this problem?

Thank you all,

aa