I have the same problem when started.
If you want to see "more big" you image without clic on it, do this:
Use insert image tool Not use attach file
Compressed the image .jpg and the dimensions, no more than 600 x 600 pixels (this work in some of my documents)
Nice work CM Watermark.
What version of Pro/E was used and what metology do you use for assembly that increible number of parts?