Hi mahag,
I may jump in for Paul here...
Thank you for the screenshots!
VSL5.tiff tells me, that you have in fact not yet installed Overdrive - the CAB files are only the downloadable archives, not the installed collection.
Please launch the Library Installer from /Applications/Vienna Instruments Pro/ and point it to the package.info files you have in the OD VSL folder on 2nd HD - you will have to install both Standard and Extended Content one at a time, but please install them to the same location.
renske_6234: Please launch Directory Manager, remove all eventual entries and reassign your Sample Data folder(s) directly from the Finder/Explorer by Drag & Drop(!) - does that make a difference?
Best, Marnix