m.fadeinAnimation.control = "start"
because it is being called more then once because the bitmapWidth is changing, sometimes several times per item focus change.
That seems wrong and bad. I haven't looked at that example in a bit but shouldn't "OnBackgroundLoaded" be called only once?
Usually blinking screens happens when a content set is assigned to an already-on-screen component and the solution can be to temporarily hide that component while the content is being updated.
hope it may help