Controlling the active menu item
The "Hosting" li item is only active if you're on the Hosting page.  If you're on a child page of "Hosting" won't be the "active" item, it will be the "active-trail".

You can change your navigation CSS to make the link look properly by changing .active to .active-trail:

.navigation li a:hover, .navigation .active a {
    background: none repeat scroll 0 0 #FFFFFF;
    border-color: #E99719;
    border-top-left-radius: 5px;
    border-top-right-radius: 5px;
}


to

.navigation li a:hover, .navigation .active-trail a {
    background: none repeat scroll 0 0 #FFFFFF;
    border-color: #E99719;
    border-top-left-radius: 5px;
    border-top-right-radius: 5px;
}


What might have confused you is that the link itself has a class of active, but its li wrapper does not.