Hi,

I get a ruby script error (and no graphic), if I use the attached 
example with pdftex.

[..]
(./textext.tuo)TeXExec | processing graphic 'textext-mpgraph'
r:/tex/texmf-context/scripts/context/ruby/base/tex.rb:2108:in 
`doruntexmp'TeXExec | option 'batchmode' is set to 'true'
TeXExec | option 'once' is set to 'true'
TeXExec | option 'nomprun' is set to 'true'
TeXExec | option 'output' is set to 'dvips'
TeXExec | option 'randomseed' is set to '217'
TeXExec | option 'filename' is set to 'textext-mpgraph'
TeXExec | option 'mainlanguage' is set to 'standard'
TeXExec | option 'bodyfont' is set to 'standard'
TeXExec | option 'language' is set to 'standard'
TeXExec | option 'engine' is set to 'standard'
TeXExec | option 'distribution' is set to 'web2c'
TeXExec | option 'texformats' is set to 'en nl mptopdf'
TeXExec | option 'mpsformats' is set to 'metafun'
TeXExec | option 'progname' is set to 'standard'
TeXExec | option 'interface' is set to 'standard'
TeXExec | option 'runs' is set to '8'
TeXExec | option 'backend' is set to 'standard'
: undefined local variable or method `data' for #<TEX:0x2cf6244> (NameError)
    from r:/tex/texmf-context/scripts/context/ruby/base/tex.rb:1617:in 
`runtexmp'
    from r:/tex/texmf-context/scripts/context/ruby/base/tex.rb:1151:in 
`processmptex'
    from r:/tex/texmf-context/scripts/context/ruby/base/tex.rb:1148:in 
`each'
    from r:/tex/texmf-context/scripts/context/ruby/base/tex.rb:1148:in 
`processmptex'
    from r:/tex/texmf-context/scripts/context/ruby/texexec.rb:73:in `mptex'
    from r:/tex/texmf-context/scripts/context/ruby/base/switch.rb:133:in 
`send'
    from r:/tex/texmf-context/scripts/context/ruby/base/switch.rb:133:in 
`execute'
    from r:/tex/texmf-context/scripts/context/ruby/texexec.rb:787

systems         : begin file textext at line 4
[MP to PDF] (./textext-mpgraph.1 (./textext.tuo)
[..]


Best wishes, Peter