I've got 5.6.0 installed and everything works provided that I go to www.mydomain.com/default.aspx.   If I go to just www.mydomain.com , I get the Error page with the button that says Return to Site.  When I click on the Return to Site button, it takes me to the default.aspx.  Looking at the source for the Error page, I see this:
<form method="post" action="ErrorPage.aspx?status=500&amp;error=Violation+of+UNIQUE+KEY+constraint+%27IX_PortalAlias%27.+Cannot+insert+duplicate+key+in+object+%27dbo.PortalAlias%27.%0d%0aThe+statement+has+been+terminated." id="Form">

I have 2 records in the PortalAlias table.  Do I need to remove them both and let it try to insert one again?

So, what do I need to do to make www.mydomain.com navigate to the default.aspx page?  I have the default.aspx as the only home document in the IIS settings.

Thoughts and help please!

Thanks,
Greg

Thanks Chris.  I did install the 5.6.1 RC and it did fix this issue but somewhere along the upgrade path, it completely wiped out the calendar events and made the document links not work.  I fixed the download links for the documents by manually modifying the web.config to use v4.0 instead of v2.0 for the LinkClicked handler and others per another forum post I found.  Thank goodness that was easy enough.  However, the calendar events disappearred.  They are still in the database so I'm not sure what happened there.  In the meantime, I reverted back to my original 5.4.1 installation and upgraded it to 5.4.4 and all is well.  So, I am just going to leave it there unless the need arises to upgrade. 

Thanks,
Greg