I've been battling for a while how to localize the menu for my site with different languages

 The solution turned out to be rather simple in the end I changed the site map line to this

<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" enableLocalization="true"> 

and then in the title tag of the site map I replace the title like so

<siteMapNode title="$resources:stringsRes,adm_Navigation_Homepage"

Only issue is if you use the site navigation menu to make changes it will over ride this info. 

Also I put in the title description the localization name adm_Navigation_Homepage

And then in the default.aspx.cs I changed line 112 to this
Title = (string)GetGlobalResourceObject("StringsRes", _page.Title);
 
Cheers