On 25 Apr 2016, at 16:34, Hans Hagen <pragma@wxs.nl> wrote:

On 4/25/2016 3:46 PM, Meer, Hans van der wrote:
Thanks,

Your reply popped up here exactly the moment I saw the light! Must be
something
Messed up the order things:

Was:
\scale[\scalesetting]{%
   \expanded{\useMPgraphic{\xmlatt{#1}{name}}{\xmlatt{#1}{parameters}}}}%

And of course had to be:
\expanded{\scale[\scalesetting]{%
   \useMPgraphic{\xmlatt{#1}{name}}{\xmlatt{#1}{parameters}}}}%

is the \expanded really needed?

Sure, is needed. Checked it again.
I define \scalesetting as 
\edef\scalesetting{scale=\xmlattdef{#1}{scale}{1000}}
But I am not sure why this needs the expansion..

The enclosing \rotate[rotation=\xmlattdef{#1}{rotation}{0}]{...} does not need the \expanded.

Hans van der Meer