Bug 134266 [Wizard] Page description not set if page message already set
Since page messages such as errors and warnings used to be displayed in the same widget as the page description, code was put in place in WizardDialog#updateDescriptionMessage() to avoid setting the page description if there was already a message. As of 3.2 M6 there is a separate widget for displaying error and warning messages and so the page description should always be set.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
for (int i = 0; i < pages.length; i++) {
            IWizardPage page = pages[i];
            if (page.getControl() != null) {
				page.getControl().setVisible(false);
			}
        }
    }
    /**
     * Creates the Previous and Next buttons for this wizard dialog.
     * Creates standard (<code>SWT.PUSH</code>) buttons and registers for their
     * selection events. Note that the number of columns in the button bar composite
     * is incremented. These buttons are created specially to prevent any space 
     * between them.
     *
     * @param parent the parent button bar
     * @return a composite containing the new buttons
     */
    private Composite createPreviousAndNextButtons(Composite parent) {
        
        ((GridLayout) parent.getLayout()).numColumns++;
        Composite composite = new Composite(parent, SWT.NONE);
        
        GridLayout layout = new GridLayout();
        layout.numColumns = 0; 
        layout.marginWidth = 0;
        layout.marginHeight = 0;
        layout.horizontalSpacing = 0;
        layout.verticalSpacing = 0;
        composite.setLayout(layout);
        GridData data = new GridData(GridData.HORIZONTAL_ALIGN_CENTER