[NTG-context] Strange MP problem

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.