I have a site map in top of my master page , When i run in Firefox the first node is "Skip Navigation Links" What's that ? And How can i get rid of that ? It's noticeable that that's not in IE .
The Skip Navigation is there for accessibility purposes. If it's part of an ASP.NET Menu, and you want to disable it, try setting the attribute:
SkipLinkText=""
See this thread for details on SkipLink and Menus.