Bug 135790 ClassCastException in RowData.
ClassCastException is thrown in RowData line 81(IBaseExpression expr = ( IBaseExpression ) valueExpressions.get( index - 1 );).
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ListingElementExecutor.java
* @param visitor
	 *            the visitor object that drives exection
	 */
	protected ListingElementExecutor( ExecutionContext context,
			IReportItemVisitor visitor )
	{
		super( context, visitor );
	}
	/**
	 * access the query and create the contents. the execution process is:
	 * <li> the cursor is at the begin of result set.
	 * <li> call listing's onStart event
	 * <li> create the header
	 * <li> for each row:
	 * <ul>
	 * <li> call onRow event.
	 * <li> if the row start some groups, create the group header for that
	 * group.
	 * <li> create the detail row.
	 * <li> if the row end some groups, create the group footer for that group.
	 * </ul>
	 * <li> create the footer.
	 * <li> call the onFinish event.
	 */
	protected void accessQuery( ReportItemDesign design, IContentEmitter emitter )
	{
		ListingDesign listing = (ListingDesign) design;
		rsetCursor = -1;
		outputEmitter = emitter;
		int groupCount = listing.getGroupCount( );