Hi Keith,
I do not know how this can work.
Gramps writes the media path into the database for each tree.
So if you set a media path under Linux the Windows computers try to read the media from this path, if they open the same database.
So you set Z:/Gramps/Images as media path under Windows the Linux computers can not use this.
By the way…this path also Windows computers cannot read, it must be Z:\Gramps\Images.
If you set /mnt/Aamba/Gramps/images as media path under Linux the Windows computers cannot read this path.
So you must switch the media path every time you switch the OS.