A work round is to scan the image as normal and then insert the image from file. I prefer to do it that way as I have a back up copy of the image and don't have to rescan if I lose it or want another copy elsewhere.
You should be able to open the image and flip it which can be done with more modern versions of PagePlus.
I have used PagePlus from some of its early versions and it is good. The version on the disc was free for a reason - it's old and is really a trial to get you to buy the later versions.