I just wanted to report a fix that my host, Aiso.net, helped me with. I upgraded from WP 2.5 to WP 2.5.1 using the automatic upgrade plug-in. I got stuck in the "you must upgrade your database" loop. When I would click upgrade, the page would go blank.
Steve discovered that it was the following line with help from the following topic on the forums:
and line deleted: ALTER TABLE comments ADD KEY comment_approved (comment_approved)
I assume although I can't verify now since the line is gone that it is in the following file: wwp-admin/upgrade.php.
When I go back to my back-up to look at the 2.5 upgrade file, that language is not there. Perhaps it is drawn into 2.5.1. from somewhere or is new code?
In an event, by deleting that line, my site is up and running.
Should this be reported as a bug or is it only my blog having this problem? (Caution, copy the file before you delete the line so in case this fix does not work for you.)
Can anyone with a lot of wordpress experience comment if this is a viable fix so it can help others? Anna