Acrobat "forgets" about duplex mode

Question

I am using Acrobat X Pro on an Intel MacBookPro with OS 10.6.8. I have a networked HP ColorLaserJet 5550dn printer with duplex unit which works just fine in any other application. If I have a multi-page .pdf document I want to print from Acrobat (or, for that matter, Reader!), I get the Acrobat dialog box instead of the standard Mac one. Of course, it doesn't have a "duplex" option, so I click on the "Printer..." button in their dialog box. I can then set up duplex printing and it works just fine. Here is the problem: The next time I start Acrobat and print the VERY SAME DOCUMENT, it comes out single-sided, wasting paper. This is true even if I do NOTHING in between (no other print jobs etc.). In other words, by layering their proprietory print dialog box over the Mac one, apparently Acrobat is incapable of "remembering" from one print incident to the next to submit the Duplex command. Strangely, if I simply go through the chain "Print" -> press the "Printer..." button in the dialog box, I see that duplex is still selected, and if I then simply click "Print" in both the Mac and the Acrobat dialog boxes, everthing works as expected - twosided output. So going through the Mac printer dialog box apparently "jogs the memory". Ironically, by default you get a WARNING when clicking on the "Printer..." button in the Acrobat dialog box!
So, for now I'll have to remember to jump through the extra hoops every time or I'll waste more trees. BTW, a nearly 1-hour long "chat" with Adobe Support didn't resolve the problem, but messed up some more things instead.

Answer 1

O.k., this works indeed for this ONE document (if I save it after changing its properties). However, I rarely print the same file twice - my problem is printing out files sent to me by others (who may not know about this property) and having to remember each time to jump through some extra hoops (either clicking the "Printer..." button or your suggestion). So the only true solution would be if I could somehow teach Acrobat to print ALL files as duplex by default (or, like all other Mac applications that use the Mac Printing interface, use whatever printer settings were used last unless specifically changed).