Regression bug, probably while migrating to Eigen

Compiling VP1Light with the HEAD of GeoModelIO leads to a completely wrong view of the Muon volumes:

Using the HEAD version in GeoModelIO:

Using an earlier version, the GeoRead in Athena's GeoModelStandalone (before the migration to the standalone repository):

I suspect it's due to the migration of the space transforms from CLHEP to Eigen.

I should compile VP1Light with previous versions of GeoModelIO to see when the regression occurred.