I have done traced in the changeset 4343 (see attached HelloSubSceneBad.png):

changeset: 4343:86380c7b3348
parent: 4312:0f0875373d19
parent: 4342:b0d67fff23fc
user: David Grieve<david.grieve@oracle.com>
date: Wed Jul 17 09:38:11 2013 -0400
summary: Automated merge with ssh://jfxsrc.us.oracle.com//javafx/8.0/MASTER/jfx/rt

changeset 4342 works fine (see attached HelloSubSceneGood.png)