I hope this doesn't end this thread Mike! There are serious issues here. I've been doing my head in all day as why are these anomilies being presented.

So I've looked at your great find relating to XPGD17 manual (Page 33)

If I search for the same in XDPX17 the manual page gives on Page 27:
Stock Illustrations
In addition to the STOCK PHOTOS, there is also a category of vector graphic STOCK ILLUSTRATIONS. All the images have keywords so you can easily search for the graphic you want. Because the original vector files vary enormously in size, graphics larger than around 300px are scaled down. Also un-grouped images are placed in a group for ease of manipulation. Because this is vector clipart, it’s re-sizable to any size without loss of quality.
Different answers. Not only that but I've experimented all day with creating squares and exporting as svg's. Often on importing the svg into Xara the square is almost double the size. At other times exporting rectangles as svg and opening in Xara they're smaller.

This is a serious bug!