Hi,
In dnn:NAV how shall I add  separator?

<dnn:NAV runat="server" id="dnnNAV" ProviderName="DNNMenuNavigationProvider" CSSControl="main_dnnmenu_bar" CSSContainerRoot="main_dnnmenu_container" CSSNode="main_dnnmenu_item" CSSNodeRoot="main_dnnmenu_rootitem" CSSIcon="main_dnnmenu_icon" CSSContainerSub="main_dnnmenu_submenu" CSSBreak="main_dnnmenu_break" CSSNodeHover="main_dnnmenu_itemhover" NodeLeftHTMLBreadCrumbRoot="" />

I've been looking for the correct attribute, but documentation on the new NAV menu seems to be well hidden. I hope that Lee or someone else can help.

check out this post where I listed the various properties available with the Nav Menu, including separator

I am able to insert a separator in my DNN Nav menu but it takes on the mousover affects of the menu item to it's right. So if the menu items gets underlined, it does. Is there a way to fix that.

For troubleshooting through CSS code for elements such as that I use the techniques outlined here:
Troubleshooting DotNetNuke Skins

Hope this helps to get you started,