Sustancia Java - Excepción extraña

Question

Estoy usando la versión 6.0 de Sustance Look y Feel en mi aplicación Java Swing. La aplicación funciona bien para mí, pero algunos de los usuarios de la aplicación, especialmente aquellos que usan Windows 7, obtienen una excepción de sustancia:

java.lang.InternalError: Unable to instantiate org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.colorchooser.ColorPalettesChooser
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.createDefaultChoosers(SubstanceColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua13ColorChooserUI.__org__pushingpixels__substance__internal__contrib__randelshofer__quaqua__Quaqua13ColorChooserUI__installUI(Quaqua13ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua13ColorChooserUI.installUI(Quaqua13ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua14ColorChooserUI.__org__pushingpixels__substance__internal__contrib__randelshofer__quaqua__Quaqua14ColorChooserUI__installUI(Quaqua14ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua14ColorChooserUI.installUI(Quaqua14ColorChooserUI.java)
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.__org__pushingpixels__substance__internal__ui__SubstanceColorChooserUI__installUI(SubstanceColorChooserUI.java)
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.installUI(SubstanceColorChooserUI.java)
at javax.swing.JComponent.setUI(Unknown Source)
at javax.swing.JColorChooser.setUI(Unknown Source)
at javax.swing.JColorChooser.updateUI(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at org.jdesktop.swingx.JXColorSelectionButton.getChooser(JXColorSelectionButton.java)
at org.jdesktop.swingx.JXColorSelectionButton$1.propertyChange(JXColorSelectionButton.java)
at java.beans.PropertyChangeSupport.fire(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at java.awt.Component.firePropertyChange(Unknown Source)
at java.awt.Component.setBackground(Unknown Source)
at javax.swing.JComponent.setBackground(Unknown Source)

Esta excepción ocurre en la última línea en este código:

JXColorSelectionButton myColorSelectionButton = new JXColorSelectionButton();

myColorSelectionButton.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
myColorSelectionButton.setFocusPainted(false);
contentPane.add(myColorSelectionButton, cc.xy(29, 19));
/**
  * Some code here
  */
myColorSelectionButton.setBackground( Color.WHITE );  // Excepton occurres here !!

No puedo encontrar un lugar para hacer esta pregunta de sustancia, así que si puedes ayudarme, eso sería apreciado.