Strange MP problem

[Tobias Burnus <tobias.burnus@physik.fu-berlin.de>]

Hello,

I have a really strange problem.
After changing a label in ghostscript (mpost terminal), I fail to mpost 
the output since the TeX file looks like

\switchtobodyfont[7.5pt]
%
[...]
\shipout\hbox{\smash{\hbox{\hbox{% line 402 gnuplot0001.mp
xtls ($1+2885.878040):($3/1.6637149187); $\Gamma_{\rm L}=1.5$, 
$\Gamma_{\rm G}=0
.2$}\vrule width1sp}}}
\end{document}

Of cause it fails at the "\end{document}", but why is it there at all?
In the metapost file are only the normal put_text(btex ... etx) 
statements (plus my verbertim "\switchtobodyfont[7.5pt]").

Any ideas?

Tobias

PS: Thanks Patrick for a5 vs. A5 help.