Several months ago I installed standard Wordpress in the subdirectory "blog" on my site. Then, last night I installed WPMU in the root directory, creating a new database for WPMU. At the time, everything seemed fine. Then several hours later my blog site started loading extremely slowly. Now, the blog is gone and when you type in mydomain.com/blog you get the setup page from WP right after you install it for the first time. When I log in to my server, I can see the database with the WP install, and I can see all the files in the blog subdirectory, so they haven't been deleted somehow.
Is WPMU interfering with the WP installation some how? Or do I have another problem?