I'm upgrading WP 2.5 (I know -- long overdue!) with WP 3.0.1. I follow these steps:
1. I extract a back up of my database using phpAdmin
2. I download the latest ZIP file from wordpress.com to my local machine and unzip it.
3. I manually copy files over using SFTP. I delete wp-admin and wp-includes and update these directories using SFTP. I manually copy over wp-content.
4. I update wp-config.php based on new settings in wp-config-sample.php.
That should do it, no? But when I go to /wp-admin in my blog, it *still claims* I'm on WP 2.5. Why? What am I missing?