Not connecting to database after upgrading from beta 26 to 28
 

I had beta 26 installed on a test site (with test database) and after upgrading to beta 28, it looks like I'm no longer connecting to my database. (my test site looks like a fresh install)

I've tried re-downloading beta 28, made a fresh duplicate of my "old" site and uploaded the re-downloaded beta 28 files to it. Then I made a new copy of my "old" site's database and had that restored over the contents of my test database and ran the upgrade. Nothing works.

I also tried clearing my browser's history after the upgrade - that didn't fix it.

Suggestions?