PM uses the GPS coordinates it finds in the file. It is very well possible that these are off, for various reasons, including a faulty GPS unit. If they are wrong in camera, the only solution would be to correct them. This you can do with PM quite easily: right click on the image and select “Set GPS coordinates”. This will open a window in which you can alter the coordinates. Either by entering then numerically, or via the map that is shown.
Enjoy,
Hayo