page in footer stopped working in beta6

[everymoment]

Footers worked in poi version 3.5-beta4. 

In 3.5-beta6 te following code says: 

            bad text 'Page &P of &N' 





public static void foot (HSSFSheet sheet){ 
     HSSFFooter f = sheet.getFooter(); 
     f.setLeft(HSSFFooter.date()); 
     f.setCenter(HSSFFooter.tab()); 
     f.setRight("Page " + HSSFFooter.page() + " of " +  HSSFFooter.numPages()); 
}