Steps to reproduce:
1) java -jar Ensemble.jar
2) switch to fireworks demo
3) resize to full screen (artifacts should be visible)
4) move splitter to left (enlarge fireworks area)

Environment:
Java(TM) SE Runtime Environment (build 1.7.0_04-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode)

JavaFX: 2.2b17_x64

Linux linux-jb96 3.1.10-1.16-desktop #1 SMP PREEMPT Wed Jun 27 05:21:40 UTC 2012 (d016078) x86_64 x86_64 x86_64 GNU/Linux

NVIDIA 6600 GT driver version 295.49