Multisite Bug Fix – Remove Subscribers from the Post Author Dropdown
There is a little bug with WordPress 3.0.1 that you may have encountered while using WordPress Multisite as the super admin. All Subscribers appear in the “Post Author” dropdown list on the post edit screen. This can be extremely inconvenient when you have several hundred users to scroll through in order to assign the correct author.
This bug has already been reported in trac and a patch to fix this issue is available. The problem should be resolved in WordPress 3.1, whenever that is released. For now the patch will work magic for you.