Ignoring my own advice to never install latest WordPress releases as soon as they come out, I upgraded my installation to WP 3.0 and shortly after to 3.0.1. Doing so broke a few things. Automatic plugin updates or installs seem to hang and so does automatic WordPress upgrade.  Let me illustrate. According to this screenshot, I need to update one of the plugins.

No problem, I click on the plugin checkbox and then click “Update Plugins”. The following screen informs me that the maintenance mode has been enabled and the plugin update is underway.

This screen never refreshes. It will continue sitting at the “Updating Plugin…” prompt until the end of time. Surprisingly, the plugin actually updates quickly, but it is not reactivated. You have to go and activate it manually.

The same issue occurs when trying to reinstall WordPress by using the “Re-install Automatically” button. The screen gets stuck on the “Downloading update” prompt. Just like with plugin updates, the reinstall works. It’s just the page that never refreshes.

Things I’ve tried to fix this (unsuccessfully):

1. Remove the “.maintenance” file from the site’s root directory.
2. Re-create ./wp-content/upgrade directory with 755 or 777 permissions
3. Change permissions of wp-content to 777
4. Clean Firefox cache and cookies
5. Use IE
6. Use a browser on another computer
7. Reinstall WP manually
8. Restart MySQL and Apache
9. Reboot the server
10. Increase PHP memory allocation via php.ini, wp-config.php, and .htaccess
11. Adding “AddType x-mapp-php5 .php” to the .htaccess

Nothing worked. The WordPress dev team seem to be aware of the issue. There is an open ticket on their bug-tracking site. For now my only advice is to stay at version 2.9. If you already updated to 3.0 or later and having this problem, add your comment to the aforementioned ticket or open a new one. This is not a critical issue, just an annoying one. Hopefully, a fix will be developed soon.