Wordpress MU, as you know, creates the "super" administrator account as "admin". First thing I always do for OSes, sites, whatever, is to create a new admin account with a different and delete the default account. It is pretty standard protocol.
I did that with my MU install and even though I was in the root blog/site and created the new user and assigned as administrator, once I deleted the "admin" user, my new user doesn't have site admin controls. How do I fix this?