Why wants PVD to open a file from an other user account?
I don't know of any specific reason why it wouldn't work, but I wonder if the program is intended to be run using a different configuration file for each user...
What happens if pvdconfig.ini is copied to D:\Dokumente und Einstellungen\
User2\Anwenderdaten\Personal Video Database?
What happens if the program is started with the -portable switch, forcing it to maintain one configuration file in the program directory?
I'm not sure what impact the location of the database is. To test the above, I would move it outside D:\Dokumente und Einstellungen, and make sure the references in pvdconfig.ini point to the new location.