I have one user at the office whose print dialog window always sets the units to inches.
He always has to change them (Settings > Units > mm).
How can you set mm's to be the primary choice?
Have you checked their MS_PLTDLG_SET_UNITS_FROM_SHEET? Do they have the same units.def file as everyone else?Also in the Print Dialog check SETTINGS > PREFERENCES > SET UNITS FROM SHEET.