BuddyPress.org

I am having the exact same problem. This is a brand new install. Here are the steps that I took:

I downloaded the latest version of WPMU (2.6.5)

I copied wp-admin, wp-content, wp-includes directories along with the files in the root installation directory to the root directory of my site.

I installed the database with no problems.

I followed the advice of the BP instructions and I created a new blog, created new posts and comments. Everything worked as expected.

I then downloaded the latest BP zip file (r598).

I copied all of the files and directories in the root directory of the zip to the /wp-content/mu-plugins directory.

I copied the buddypress-home directory to /wp-content/themes directory

I copied the member-themes directory to the /wp-content directory.

I went to the Site Admin->Themes page and selected ‘Yes’ for the BuddyPress Home Theme and ‘No’ for all the others.

Note: At this time the theme for the home page was still the default wordpress blog theme.

I then went to the root blogs (located at / according the the manage blogs page) and change the theme for it to BuddyPress Home Theme.

Now I get the 404 errors that are described above. Also, when I go to my member’s page, it says that I have no blogs, to create one. After creating another blog, the member’s page still says that I have no blogs.

I feel pretty confident that I installed WPMU correctly, but I suspect that I didn’t install buddypress to the right location(s).

Please advise.