My solution to the problem, having failed to find a resolution within Word (or the Word community) is as follows.

First save the document as a PDF file. Then, having opened it with Acrobat (I hope you have Acrobat) select all the landscape pages which you want to reverse (ie end up with the landscape header on the spine edge of the document). Once selected click on Tools, then click on Rotate and choose the option “Counterclockwise 90 degrees”, and click OK.

As if by magic all the selected pages will flip 90 degrees and you will be able to print out your document. Any non-selected pages either in portrait or landscape mode will remain unchanged.

Good luck.

PS: I note that you first posted your problem in 2010, so maybe you have found a more elegant solution in Word. If so I’d like to hear it.