The spec for UManager.setLookAndFeel(String className) says:
"className - a string specifying the name of the class that implements the look and feel"
It is not clear which name accepts the method: binary name or fully qualified name.
It looks like it accepts binary class name, but it should be specified obviously.
According to http://java.sun.com/docs/books/jls/third_edition/html/names.html#6.7 method setLookAndFeel(String className) should found inner classes defined with "." ("SampleClass.InnerClass"). However it throws ClassNotFoundException for such classes and founds classes defined with "$". Hence either spec should mention about binary name or implementation should be changed to accept fully .