If any CMS or other page contains image or flash object, the submenus are not displayed over flash or image object. The menu will appear underneath that objects. The menu can be displayed by adding some css styles. For that open corresponding css files and add the following css classes, if menus are created by ul- li tags
.menuclass ul {z-index:999;} Read More>

While installing custom module in Magento with new table, if you got the error as ‘Can’t retrieve entity config’. This may be because of you forgot to define your new entity table in config.xml file in your custom module inside tag Read More>