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/api/script/IRowData.java
{
	/**
	 * Return the value of the provided expression. The provided expression must
	 * have been bound to the current row. Otherwise, it returns null.
	 * @throws ScriptException 
	 */
	public Object getExpressionValue( String expression ) throws ScriptException;
	/**
	 * Return the value of the i:th expression in the current row. Null will be
	 * return if the i:th expression doesn't exist.
	 * @throws ScriptException 
	 */
	public Object getExpressionValue( int i ) throws ScriptException;
	/**
	 * Return the number of expressions bound to the current row.
	 */
	public int getExpressionCount( );
}