Bug 119076 [Markers] ArrayStoreException when multiselection in Problems view includes category
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ProblemView.java
}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.action.Action#runWithEvent(org.eclipse.swt.widgets.Event)
			 */
			public void runWithEvent(Event event) {
				if (isChecked()) {
					IDEWorkbenchPlugin
							.getDefault()
							.getPluginPreferences()
							.setValue(
									IDEInternalPreferences.PROBLEMS_HIERARCHAL_MODE,
									false);
					regenerateLayout();
					getViewer().setSorter(buildSorter());
					getViewer().refresh();
				}
			}
		};
		flatAction.setChecked(!isHierarchalMode());
		return flatAction;
	}
	/**
	 * Resize the category column in the table.
	 */
	protected void regenerateLayout() {
		TableLayout layout = new TableLayout();
		getViewer().getTree().setLayout(layout);
		ColumnLayoutData[] columnWidths = getDefaultColumnLayouts();