Hi, Stirling
Check your C:\ folder for other Mach3 folders, Art sometimes uses a different Mach3 folder (Mach3184...) install path in the installer program.
If you didn't change it during your install of Mach3 then you may find your old Xml in Mach3 folder and your new Mach3 in Mach3184... folder.
Maybe this will help, Chip