this occured to me several times during planar figure (measurement bundle testing):

load pic3d (or other image with non-uniform spacing),
create a planar figure,
check if spacing of planar figure is equal to the one of the image it was drawn unto.

_sometimes_ it happens that the standard spacing (1,1,1) was set.
i didn't figure out a special way when this occured, or special combinations with other plugins. A behaviour was consistent over an open session with MITK, when re-opening MITK Workbench the behaviour sometimes changed ..

can someone else please test if this is reproducable ?
(i was working on linux)