Blocker: This is a regression in the 1.2 release (it was working previously in JavaFX 1.1). This defect was found in JavaFX 1.2 build 10.

If you create a Scene and set a stylesheet, it immediately applies to all the nodes contained in that Scene. However, if you later add new nodes to the scene, those nodes do not get styled.

A simple example to reproduce this follows (2 files):
SkinningTest.fx:
def rectBox:HBox = HBox {};
Stage {
    scene: Scene {
        width: 200
        height: 20
        stylesheets: "{__DIR__}skin1.css"
        content: rectBox
    }
}
Timeline {
    keyFrames: for (i in [0..10]) KeyFrame {
        time: 1s * i
        action: function() {
            insert Rectangle {
                id: "surface"
                width: 20
                height: 20
            } into rectBox.content;
        }
    }
}.play();

skin1.css:
#surface {
  fill: red
}

This program adds in 10 rectangles, 1 per second. Due to the stylesheet set, the rectangles should have a red fill; however, they show up with the default fill color of black (a screenshot is attached).

Files to reproduce this issue are attached.