The JavaFX 2.1 SDK no longer contains the binary version of caspian, "caspian.bss" - only the text .css version:

/fx21/b19/sdk/rt/lib $ jar tvf jfxrt.jar |grep -i caspian\\.
115078 Tue Mar 27 11:47:32 PDT 2012 com/sun/javafx/scene/control/skin/caspian/caspian.css

This took place in controls-scrum #54 (see PERF-231 for details), though I believe it was unintentional.