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/TableItemExecutor.java
}
	protected void accessGroupHeader( ListingDesign list, int index,
			IContentEmitter emitter )
	{
		groupIndex = index;
		TableGroupDesign group = ( ( TableItemDesign ) list ).getGroup( index );
		if ( group != null )
		{
			String pageBreakBefore = group.getPageBreakBefore( );
			if (DesignChoiceConstants.PAGE_BREAK_BEFORE_ALWAYS.equals(pageBreakBefore))
			{
				needPageBreak = true;
			}
			if (DesignChoiceConstants.PAGE_BREAK_BEFORE_ALWAYS_EXCLUDING_FIRST.equals(pageBreakBefore))
			{
				if (rset.getStartingGroupLevel( ) > index)
				{
					needPageBreak = true;
				}
			}
			TableBandDesign band = group.getHeader( );
			if ( layoutEmitter == null && tableInfo.hasDropCells( index ) )
			{
				layoutEmitter = new TableLayoutEmitter(
						( TableItemDesign ) list, emitter );
				outputEmitter = layoutEmitter;
			}
			band.setBandType( TableBandDesign.GROUP_HEADER );
			band.setBandLevel( index );
			accessTableBand( band, outputEmitter, null );