The Copy Count is usually a specific function of the printer's driver. PS just interfaces with that, and usually pretty well.
Looking at your link to the other thread, I normally use Noel's method, as I am usually setting other properties in my printer driver's console. However, I have seen one of my printer drivers (an HP All-in-One) that then dumps the Copy Count, so I add that, at the very end, just before Print/OK.
I think that most such issues are going to be printer, and printer driver specific. What works perfecly for my Epson, does not seem quite so smooth on my HP.
Perhaps Chris Cox can offer more background, regarding PS's interface with printer drivers.
PS - I am a very low-volume printer, so seldom have large jobs queued, and am normally doing just a few copies, and one job at a time. That means that I am most likely not the best person to comment on higer-volume workflows.
This is a pretty well-known issue with PS CS5 and some printer drivers, and it's not just the copy count, but could embody all the printer settings on the page. There somehow seems to be an intermediate staging area for settings, which can make things as confusing as heck, because settings changes you try don't seem to work (they're just not working right away).
There's a workaround... In the Photoshop Print dialog, after you've set the copy count, operate the [Print Settings...] button to open the driver-specific settings then OK out. That seems to get your Print dialog settings to "take" this time.
Thanks, Noel, I will try the work-round next time I'm printing. By "pretty well-known issue" do you mean that it has been formally log and accepted by Adobe as something they need to fix? Or just that users have been talking about it?
Bill I can confirm that it's ONLY PS that has the problem. No such issues when printing via LR or via other apps.
We talked about it here on the forum not long after Photoshop CS5 was released, and as I recall Chris Cox acknowledged it.
More like "it's a bug in the Windows support for older printer drivers that Adobe has to work around".