Scene Builder's Preview window does not refresh correctly

(Using JavaFX Scene Builder 1.0 ea b10 on WinXP SP3 + JDK 1.6.0_25)

1. When previewing a fxml file, if I drag the corner of the preview window to enlarge it, the preview
    window is not refreshed

2. Sometimes the toolbar of the Builder's main window(not the preview window) disppeared

3. When switching the preview window and the main window from/to back/front, the preview window
    is not refreshed, but if you resize the preview window a little(one pixel is enough) the preview
    window will be refreshed

Meanwhile, the console repeatedly printed out below

java.lang.NullPointerException
        at com.sun.prism.impl.BaseGraphics.drawTextureVO(BaseGraphics.java:365)
        at com.sun.prism.impl.BaseGraphics.drawTexture(BaseGraphics.java:334)
        at com.sun.prism.impl.ps.BaseShaderGraphics.drawTexture(BaseShaderGraphics.java:103)
        at com.sun.prism.impl.BaseGraphics.drawTexture(BaseGraphics.java:325)
        at com.sun.prism.d3d.D3DSwapChain.present(D3DSwapChain.java:35)
        at com.sun.javafx.tk.quantum.PaintRunnable.run(PaintRunnable.java:332)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
        at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
        at com.sun.prism.render.RenderJob.run(RenderJob.java:29)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at com.sun.javafx.tk.quantum.QuantumRenderer$ObservedRunnable.run(QuantumRenderer.java:67)
        at java.lang.Thread.run(Thread.java:662)

I recorded the screen as a video, please see attached SceneBuilderIssue.wmv(6,946,810 bytes)

Below are answers to Engineering's questions:

Q1) Was screen lock (or a screen saver) ever activated after you started the program?
A1) No, screen saver was not activated, but I realized that something related to screen saver was
changed - the timeout for turning off the power of screen was changed to 1 min if battery is used,
and 15 min if AC power is used.

I guess if this is caused by that something was "broken" by the program and the settings
are all reset.

Q2) Is this consistently reproducible? On more than one system?
A2) Yes, it is always re-producible. I have 2 XP laptops(I have only XP laptops), the slower one is
Lenovo 3000 V200(CPU is Core2Duo T7100) on which I need 10 seconds to re-produced it, while,
the faster one is Thinkpad T61(Core2Duo T9300) on which I need over 60 seconds to re-produced