NullPointerException in rendering

NullPointerException seen in rendering loop. This stops the screen updating after running for a minute or so.

(in javafx 2.0.1)
java.lang.NullPointerException
at com.sun.prism.impl.BaseResourceFactory.createTexture(BaseResourceFactory.java:116)

(in javafx 2.0.2)
java.lang.NullPointerException
at com.sun.prism.impl.BaseGraphics.drawTextureVO(BaseGraphics.java:365)

...See attachments for full trace.

Details
 - Code to reproduce problem attached. Note this is a highly simplified version of what I'm doing - I know a moving red rectangle can be done more easily/robustly in native JavaFX !
 - App was run with following options "-Djavafx.verbose=true -Dprism.verbose=true -Xmx1200M"
 - Seems to be memory related - if I allocate a decent chunk of memory upfront - say 400M then problem occurs almost instantly.
 - A slightly different exception seen after upgrade to javaFX 2.0.2 => Console outputs for both versions attached.
 - also attached DxDiag.exe output in case direct X related.

Background (why am I doing this!)
We need to display constantly changing pixel data at around 1280 x 400 resolution, changing at rates of 4Hz or so.
This was previously achieved in previous Swing systems using JPanel.paintComponent() + a buffered image .
There is no "nice" way to do this in JavaFX, so updating via impl_fromExternalImage() is used.
If anyone can come up with a more robust way of doing the same thing please let me know