this is now resolved,
I have manged to add the image to the themeroller theme in order that it can be selected for both the screen swatch and the container swatch from the builder. Once the image has been added to the theme.
This confliction between these two swatches are what has been causing the problem with glichy, horrible white flash between screens.
this solution works very well for textured tiles for eg. apples stripe and linen, (dont know about images)
Because it in the theme no need for container js or custom css,
makes things more native and quicker!
It has taken a long time to get pass this problem,
there is a platform allowing developers to use themeroller and they have an uploader for the background image,
I hope apperyio consider this as an option as it add a real native feel to ios apps and gets rid of that horrible flash between screens while using themeroller
thx