I was hoping I could add a "no follow no index" tag, but there doesn't seem to be any way to edit "default.aspx" or get it excluded. I wonder if I would have more success submitting my website using the /Pages/default.aspx instead of the actual domain.
More frustrating is that on the "default.aspx" page, there is a tree view where it is shown as being a secondary page, and clicking on the top level brings me to the correct homepage, or at least redirects properly.
And I will try the Sharepoint workaround, thank you. Here's to hoping MSFT updates their website software so that it works with their search engine.
-Adam