The only way that I can think of to do this is to make two different views. One page will be portrait and then the next landscape. You can change how each view prints by opening the View Properties dialog box by double-clicking on the view name in the Views task pane.
Other than that you could use the process described above and print one page at a time.
File -> Print only page 1 -> Properties -> Portrait -> OK
File -> Print only page 2 -> Properties -> Landscape -> OK
Hope this helps, let us know if you have any more questions!
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Matt Faus
InfoPath Dev Texas
Matt Faus / Microsoft InfoPath MVPQdabra® Software / Streamline data gathering to turn process into knowledge