This question is related in part to a previous question I have asked.
I have tried printing an A3 mxd with the Print Active View code as published by ESRI and have changed only one line of code and that is, to change it to A3 size.
docPaper.FormID = 8;
This forces it to a size of A3 instead of the default 0 Letter size (esriPageFormLetter).
The map prints out fine(ish) but it is not to scale i.e. the map is supposed to be 1:10000, but the space between the graticule grids is 9.7cm, not 10cm as it should be.
If I print the EXACT same mxd out, but via the manual method i.e. in ArcMap itself, File -> Print. The scale is correct and it measures 10cm.
Important to note that I have not changed any of the Page and Print Setup settings between the two prints.
Why would it do this?
See pic below to help understand whats going on.