Has to be a problem in the print driver. Did you set the driver to print duplex? That's one level deeper than the print setup in the Print Booklet dialog.
the printer has been printing duplex with no issues from other programs. I clicked on "printer" in the "print booklet" dialogue, and allowed duplex "two sided" option.
however it still doesn't seem to work.
Other programs don't mean a thing to ID and printing. The bad news is I'm a Windows user and the dialogs are a little different and I never can remember which buttons are which on the Mac. You need to get all the way to the printers driver settings dialog -- might be called printing preferences or something similar, and it may be one level deeper than you've gone so far.
Or it could be that ID and that printer just don't get along.