Separator Not Rendering in IE 8

[Anthony]

I have a databound RadMenu, bound to a datatable that comes from SQL Server.  For rows that should be separators, I check a "ItemType" property on DataBound, and set the RadMenuItem accordingly:

Protected Sub Menu_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadMenuEventArgs) Handles Menu.ItemDataBound
       Dim menuItem = DirectCast(e.Item.DataItem, dsAdmin.MenuItemRow)
       If menuItem.MenuItemType = "Separator" Then
           e.Item.IsSeparator = True
       End If
   End Sub

So what I'm trying to achieve is to be able to put in a horizontal separator in between items.  The problem is that this renders perfectly fine in Firefox and Safari, but IE 8 does not render the horizontal separators. 

I've tried adding and removing Text to the RadMenuItem designated as the separator, tried adjusting its Height, among other things, and can't seem to get it to render.  I'm using Web20 skin, no special CSS applied to any telerik controls. 

Any thoughts on the matter?