A nice bug combining all the broken features of blender:
Particles, duplis and multiple scene dependencies.
Fortunately this was solvable: Basically, we need to
make sure derivedmesh for dupli instance is generated before
obmat is overriden. This also makes sense, since no instance
has "true" obmat apart from original. Lazy initialization of
derivedmesh just does not work here (or it -does- work but first
use should be before instance drawing).
Fingers crossed nothing else breaks after this...
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