If you are using <cfmenu> and <cfgrid> and you have an overlapping of the menu items by cfgrid header (a part of menu is hidden behind cfgrid header) you must add to your CSS a following style:
#myMenuId .yuimenu {
z-index: 300003;
}
This problem is caused by some "yui" CSS style with z-index set to 1, while grid related styles have z-index bigger than 200000.