What I\'m trying to achieve is to override the start activity animation.
The animation should give the impression that the old activity is on top of the new activity
Actually, I've found a property called android:zAdjustment in the animation files.
If I put android:zAdjustment="bottom" in hold.xml (screen 2) and android:zAdjustment="top" in push_down_out.xml (screen 1) then I can get the desired effect.
This gets around the z order issue (I assumed it was an issue with animation timings so I was barking up the wrong tree).
John