Seeing as no-one else appears to have this problem it might be with this pc (Acer Iconia).
Whatever model is in Sketchup 2015 - even the default ‘man’ with nothing else created - any export is flipped both horizontally and vertically. Printing (including Print Preview) results in a flipped image with back-to-front text, exporting to file does the same. Even exporting to Layout does the same.
I experienced the same thing with Sketchup 2016 on Windows 7. It happened as soon as I used the dimensioning tool on the RIGHT side of an object, moving the labels to the right of that object.
For whatever reason, that told Sketchup to very carefully flip the drawing left to right, preserving the dimensional dimension text.
The flip occurred BETWEEN the preview print and the print steps.
I fixed it by deleting those measurements on the right side.