After having some trouble with the migration, I thought the easiest way to make sur my WP files were clean would be to upload the new version (2.3.1) cleanly.
Then I tried to access the "update" function, and it tells me I cannot access the database.
I checked the wp-config.php, and the username and password are definately right.
I'm using 1 & 1 for hosting, if anyone's familiar with them. On the MySQL admin page, it lists your dbs, and shows a "host name" for each. I wasn't sure if this meant that was what needed to be in the '99% sure you won't need to change this' field, so I've tried it both ways. Still no luck.
My fear is that this is somehow related to the comment they have posted at the top of that page:
Your MySQL databases are stored behind a firewall to protect your data. You can only access each one exclusively through your server. Direct access to your MySQL databases using a home PC (external ODBC connection) cannot be established.
*IS* that the problem? Or am I missing something else??