Installation isn't yet putting in all the right data for user groups. To make your user a sysop, do something like this: INSERT INTO user_groups (ug_user,ug_group) VALUES (1,3);Media where you would use the user_id and group_id values for the appropriate user and group. The default 'Sysops' group presently is id number 3.

-- brion vibber (brion @ pobox.com)

I followed your advice, noticed some changes, but I still haven't the correct rights to edit MediaWiki:Pages .