Just getting back to this a moment.  The same issue appears after introducing a third M4, saving the scene and reopening.  I looked at the parameters panel for the head and found the morphs still for the figure, however the dials were reset to zero (head, lower jaw, upper jaw).  For all three haed parts mentioned, I reset the dial values to 1 to activate the morph, but after each reset, I also right clicked the dial and memorized the morph value.  Afterwards, a fourth M4 was introduced into the scene, the file resaved, Poser rebooted, and the scene reopened.  This time the Orc remained an Orc.

I believe the solution might be to go to each dial for the head morph and memorize the individual affect parts.  That would be the head, the upper jaw and the lower jaw.  If you do any custom changes, I would recommend spawning a new head morph and memorize those dial values before saving.