PAGE SETUP LOST/CHANGED ON DUPLICATION

Question

Using Pages '09 (v4.3) to produce a custom envelope for printing, discovered a problem of Page Setup info being lost/changed when you Duplicate a file or when trying to print from a template produced from that file.
I set up the file using Merge Fields for the recipients, working from a Master and using the File>Duplicate command to make a copy of the file for examining the output.  Everything looked good in the Print Dialogue displays, and also when checking by, for example, Saving PDF to Preview. On running an actual test print, however, it came out a total mess; text on the envelope in the wrong place and the wrong orientation, totally unuseable.
On examination I found that the Master's Page Setup info had been changed in the duplication:
"Format for ....." changed from <My printer> to "Any Printer"
"Paper Size"      changed from <My custom size & name> to "Other", although dimensions were retained
"Orientation"       changed from Vertical/Portrait to Horizontal/Landscape
This happened each and every time I duplicated the file,and I learned to simply go in and change the Page Setup info before printing.  Once happy with the design, I saved the last good Master off as a Template so I could call it up from My Templates for future use.  Unfortunately, I quickly discovered that the same thing happens from there.  Drag the vcards into the displayed file, set up the Mail Merge, and go to Print and all will look well but, once again, actual printouts will be messed up and, on examination, for the exact same reasons.
Page Setup is being messed up in a way that isn't visible on any of the visual displays before actually printing; there, all looks as you think it should and it appears that the printing should go well.  The info actually being sent to the printer, however, is incorrect. So, there seem to be two errors here, both linked:
The Page Setup info is not being reflected in the images or icons showing what the printed output will look like, and
The output produced at the printer is not what is shown before you print.
I'm far from a Pages expert so I can't help but wonder:  Is there some essential step I've been missing here? Any help or suggestions would be greatly appreciated.

Answer 1

Slight correction to the above: The corruption/change of the Page Setup information occurs as the template is selected, i.e, the new "Untitled.." window opens. If you go ahead and change the info back to what it should have been, what it was saved as when the template was created, then all works normally.
Same is true of the duplication: The setup info changes as soon as you dupe the file.  The original will still have the correct info, but the copy now shows the same stale default values (terms used might not be appropriate).