I have not verified this but......
THERE'S ONE CATCH. See below.
<browsers>
<browser refID="safari1plus">
<controlAdapters>
<adapter controlType="System.Web.UI.WebControls.Menu" adapterType="" />
</controlAdapters>
</browser>
</browsers>
THERE'S ONE CATCH. Safari will crash when the browser window is too small to contain all the items in the menu and you hover over then out of the menu. I can not confirm this is true for Safari in general, but I have consistently seen this behavior on a Mac with OS X 10.3 and Safari 1.3, so be sure to test this case. This might be the reason that Microsoft decided to render an alternative menu for Safari.
Basically the refID matches a browser id in the original browser configuration files for the .Net framework. In our custom .browser file we override the control adapter settings for the asp:menu control for this specific browser.
Also for those who are using a StaticPopOutImageUrl and are experiencing a Spacing issue with Firefox and Safari, use a CssClass for the StaticMenuItemStyle for padding (Don't use the StaticMenuItemStyle's HorizontalPadding property)
<StaticMenuItemStyle CssClass="staticMenuItem" />