Hallo Ben,

Thank you for explaining your setup.
When I understand things correct I now copied your category hierarchy on my system, the categories now being:

@All
.Originals (the "@All" NOT "Versions" container)
..Child 1 from originals containing both masters and versions
..[...]
..Child n from originals containing both masters and versions
.Versions

When I run the script I assign the following:

Category =@All Not Versions -> Originals
Category containing Masters -> Originals
Category containing Versions -> Versions
Property with =DateTimeOriginal= -> Date

Wen I run the script for a "FULLY Automatic MASTER / VERSION Check" it reports

Images in Database 7925
+Originals / Originals 7925 / 7925
+Versions 0
Originals without Versions 7925
Versions without Originals 0
Images with invalid DateTimeOrig 151

For what it is worth, on file-level I use quite long paths names.
Let me just copy some file names for example:
A master file identifier:
D:\My Documents\My Pictures\Foto's\2006\2006-09-09\20060909_3266.CR2
A version of that file is:
D:\My Documents\My Pictures\Foto's\2006\2006-09-09\Converted\20060909_3266_DxO_raw.jpg


I just hope I am goofing up somewhere