This happens from time to time. I have seen it many times, even on dotnetnuke.com. I think it has something to do with DotNetNuke not recognizing your browser properly  (keyword: ASP.NET "BrowserCaps") and thus giving you some downgraded SEO optimized search engine crap. In a perfect world, search engines and normal visitors would be served the same markup. In a less than perfect world, unknown clients should be served the normal content. Unfortunately, in the DNN world, the default is fail. DNN thinks you are a web crawler..  

This happens with the default skin, or nav provider when using FF 3.6+. Not sure what DNN version this affects but I'm sure it is a recent one (5.4+). While it may be easy to say "Switch to a different menu provider" newcomers aren't going to find that a satisfactory answer. This DNN site showcases the issue, affecting the perception, real or perceived, of the product quality as a whole. Would you buy a professional version if the menu was broken for a major browser out of the box? If you were a newcomer and just installed DNN and saw this, what would you think about the product? Humorous that some think this is trivial bug.

@Wells & Eric
My comment was strictly for the line  "Unfortunately, in the DNN world, the default is fail."
Which I don't agree with.
I agree this should be fixed, I just wanted to post this is strictly an issue with the menu provider.
The previous poster assumed fail is a general DNN issue.

The issue is that NAV tried to see what browser you are using and if it fails (which seems to happen every now and then)  it will show you a low level menu (you are seen as a crawler)
There are are 2 core ways of fixing this:

1. Switch the menu to UL mode (examples here: http://dnnskinextensions.codeplex.com...)
(which is only supported in ASCX skins)
2. Use Telerik Menu (You can find some examples for that in the Skinning Contest)
Example: http://dnnskinexpression.codeplex.com/

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