I'm working with Adobe Reader 8.1.1 and Windows XP Pro. Using HP Color LaserJet 2605dn, which has automatic duplex printing capability.
I have PDF files that contain several pages. When I set the 2605's "Preferences" to print duplex (print on both sides of the page), it prints the pages "head-to-toe" - page 1 is right side up, page 2 (on the back of page 1) is upside down, page 3 (on the 2nd sheet of paper) is right side up, page 4 (on the back of page 3) is upside down, and so on.
I've experimented with the various settings in Reader's Print dialog box, but nothing makes all the pages print right side up.
I don't know the source of the problem: the multi-page PDFs I'm trying to print were not all created by the same person or software. Duplex printing works correctly when printing multi-page documents from other kinds of software (e.g., Microsoft Word and various databases).