When you use a customzied page size, the orientation of ADS from printing is not correct
For example, when you want to print with landscape but it always be printed as portrait.
It because the custom form is not exactly same landscape with the printer size and make the automatic determination does not work.
Resolution
Open the "print options edtior" in the tab "pdf options" select the "use external paper size"
If the option is selected :
The values of PDFPaperHeight and PDFPaperWidth are used.
Otherwise, the size is determined from the PDF file itself. In this case, the values of PDFPaperHeight and PDFPaperWidth are ignored.