Sharepoint 2010 Designer problems and ribbon stuck on loading.....

I ran into a good one today.  I had just implemented several new Sharepoint sites.  I used ControlPoint to copy the top level site to a subsite and changed the home page of the old top level site to do a meta refresh to the new sub site that I wanted to act as the top level site.  This would still bring up the old page for a brief second before the redirect so I decided to instead put in an IIS redirect.  This seemed to work great, until suddenly I couldn't open anything in Sharepoint Designer.  I started getting the infamous "The Web server at .... does not appear to have Microsoft SharePoint Foundation installed" error.  The ribbon was also stuck on Loading......I checked all the settings for designer and client integration, changed them, and changed them back.  I reset all my IE settings.

Finally I found this link: 
http://sharepoint.stackexchange.com/questions/27877/sharepoint-designer-2010-doesnt-work

It ends up that if Sharepoint can't access the top level site (which happens with an IIS redirect) then a lot of stuff starts going crazy.  The lesson here is to not mess with the top level site.