Page 12 in manual [A] 7.2 channel surround system (front height) - Speaker System setting: normal (SB/FH). It is not possible to produce sounds simultanously from front height or front wide speakers and the surround back speakers.
Additional info which might help to understand:
For 5.1 to 7.1-Front_Height expansion, DPLIIz looks likes it will have two different effects depending on the nature of the input material:
•For 5.1 source material deliberately coded with front height content [and Dolby says it will teach game developers how to do this], DPLIIz will extract Front Height speaker content [somewhat analogous to the way analog decoders unscrambled matrixed 2 channel into L/C/R/Rear]; I guess that will be mostly discrete, and have low crosstalk versus other surround channels.
•For 5.1 source material NOT specifically coded with front height content, DPLIIz will infer Front Height speaker content; I'd guess that the results will be hit-or-miss - like they are if you apply DPLIIx to (say) 2 channels CDs. If the results suck, go back to 5.1, or if you have 9 speakers attached, try DPLIIx(Movie) or DPLIIx(Music).
What I learned about Front Height Speaker listening with Pioneer Elite VSX-53 http://www.avsforum.com/t/1396279/front-height-speaker-listening-with-pioneer-elite-vsx-53#post_21694555
This should help answer 1st part of your questions.