Printers are not saved with the Print Setup step; they are saved with the actual Print step. I agree this is frustrating and unfortunate, but even the Print step is not always reliable in getting the correct printer. There are some plugins around that can handle this much more cleanly.
If printers are not saved within the print setup script step then why does it work fine in FMP 8? Also what is the relevance of the print setup script step if the printer is not saved? Is there anybody out there who uses different print setup script steps where the printers are remembered correctly? What OS do you use? What FMP version? How are your printers configured on the network?
It may have worked in FM8, although it was often inconsistent. I'm pretty sure printer specification has changed between every single version between FM6 and FM10 (10 and 11 seem to work identically).
I am speaking from experience on Windows XP. Mac works differently (and more likely correctly).
The relevance of the Print Setup step is in setting orientation and paper size, as these effect the specific output from FM to the printer (whereas the printer name and tray don't effect FM output, but only to where the data is being sent).
The disappointing part of this is that the reason for displaying the Print Setup step to users is to allow them to change printers without having to display the actual Print step (where they also may change the scope of records being printed, something we usually want to prevent). But if you want to specify record scope and/or print range in the Print step (which we ALWAYS do), then the printer saved with that Print step will override whatever the user has set in the Print Setup step.
The real answer here would be for FileMaker to provide customized setup and print dialogs (they currently use the OS standard dialogs) so that printing could actually work in a desirable and predictable way.