SharePoint 2007 menu

one of my customers are using SharePoint 2007 portal and in ipad the topglobal navigation dont show dropdown menu. That does work fine in desktop version but we are using WorxHome app from cirix which use google chrome and there i get this problem. may be solution is to convert the sharepoint 2007 navigation to responsiv menu or fix the exsisting. i want a solution to get rid of this problem.