WordPress MU

I have version 2.6.1. I follow the instructions very carefully from http://codex.wordpress.org/Upgrading_WPMU

After this, I am redirected to /wp-admin/install.php (which behaves as if I have not installed a blog at all yet.)

I get this behavior from a vanilla tar.gz of 2.6.1 and 2.7.

My main blog tables are called wp_1_comments, wp_1_posts, etc. If I continue with the installation that I am prompted, new tables named wp_comments, wp_posts, etc are created.

Any one else having this problem from 2.6.1?

- are you sure you got the MU download and not the singe WP?
- do you have another WP blog on the server?