To fix a MySQL error/warning, please follow this procedure:

1) If the error appears immediately after an upgrade, try going to yoursite/upgrade.php and running that to make sure all needed fields are added. If you've just manually upgraded from a previous version, please re-check readme.html to confirm that you've followed all steps of the upgrade procedure.

2) You'll see a bunch of debug output on the page with the warning. Relay all of this data to support via email or forum post.

Note: On a live site you'll likely want to keep the debug level at Admin -> Settings -> System Configruation -> Debug set to suppress errors for non-admins so that regular users don't see the error messages..