I installed ConTeXt in 2009 in my laptop and wrote some documents. Now I
have installed ConTeXt in other computer and tried to process some of those
documents but it doesn't work.

It looks that there is something wrong with Metapost/Metafun. I have tried
a simple program like

\starttext

Testing

\startuseMPgraphic{gh}
draw thelabel.rt("the right way",a) withcolor .625red ;
\stopuseMPgraphic

\useMPgraphic{gh}

\stoptext

Then I get:

system          > begin file kk2.tex at line 1
metapost        > initializing instance 'metafun' using format 'metafun'
metapost        > loading 'metafun.mp' (experimental metapost version two)
! terminal: >> a
>> (3,0)
! Not implemented: (unknown numeric)+(pair).
<to be read again>
                   -
thelabel->...((EXPR4)+labeloffset*laboff(SUFFIX2)-

(labxf(SUFFIX2)*lrcorner.p...
<*>  draw thelabel.rt("the right way",a)
                                         withcolor .625red ; ;
.
system          > tex > error on line 10 in file kk2.tex: terminal: >> a
>> (3,0)
! Not implemented: (unknown numeric)+(pair).
<to be read again>
                   -
thelabel->...((EXPR4)+labeloffset*laboff(SUFFIX2)-

(labxf(SUFFIX2)*lrcorner.p...
<*>  draw thelabel.rt("the right way",a)
                                         withcolor .625red ; ;


Any ideas? Thank you.