Broken links (to Document Sets) after restoring a backup to another site collection

Hi.

I wanted to make a copy of an existing site collection in order to do some testing/tweaking with existing/running workflows without disrupting the "live" site and its users.  I figured I'll just restore a backup to another site collection with a different name and in a different content database.  Backup and restore was performed via powershell.

After restoring, I'm able to get to the new site and see the home page/libraries/lists.  However, Document Sets in the document library appear to be broken.  I can see them listed and I can view/edit the metadata, but clicking on any of them gives a "File Not Found" error.  Creating a new document set ALSO seems to cause an error.  The doc set seems to end up being created, but clicking on it results in the same error as all of the pre-existing ones.  I think it fails to bring up the Document Set welcome page.  I'm using a regular, uncustomized welcome page.  Document set has custom metadata, relationship with another list within the site, different content types, and a custom workflow.

Searching around, I found a few references to broken GUIDs after restoring to a different site collection but in the same content database.  In my case, I'm using a different content database.  I even tried restoring to a different web application, but I get the same result.

Is this simply because I'm restoring a site collection that is already existent in the environment?  Even if it gets restored to a different collection/content database, would GUIDs be broken?  This makes me worry about what happens if I had to perform a legitimate restore of the original site on top of itself (overwriting).  Would things work or would they end up being broken?