I had something similar with one of my files I was sharing with FMNet at that time. If I recall correctly I had saved the file with an obscure printer and paper size .. this became the application (filemaker default printer). It seems it was causing conflicts when I was trying to specify other printer settings and orientation to other printers.
My work around to this (I'm not quite sure) on a Mac was to reset the filemaker default printer (not the Mac default printer) to a standard A4 portrait printer using the File, Page Setup on the main menu, then close the file. Then for any reports I could script the printer, settings and orientation I wished after that.
Like I say, I'm not 100% sure but it did sort out the scripting of printer orientation.