See this video: http://www.screencast.com/t/ywfccE927dar

There is a large document area, a satellite view of the document in a blue rectangle, and a another satellite view contained within a button that is used to select among the open documents. The video starts with some strange rendering artifacts in that third view. The size of the view before it is scaled to fit the button appears to be relevant. You can see that as the width of the main document is altered by dragging comonents within it, that the rendering artifacts occassionally disappear and re-appear.
You can also see that a small part of the problem is the dirty region optimization (which is NOTdisabled with -Dprism.dirtyopts=false in this case, normally I must run with it disabled.). The artifacts leave trails of garbage in the video at some points, but that is not the problem I am reporting here. The artifacts themselves should not be there. It looks like they may be related to the "i" and "?" text that are part of the small buttons in the upper right of the nodes that I am dragging in the document. The artifacts look to me like they may be the i ? characters rendered at the wrong size.

All three views are constructed the same, but the scaled views just have a scale transform applied to the containing Group.