I installed Role Scoper in my multisite, but tis was overkill for my intentions. I have deactivated the plugin, but i suspect it to still affect some of my settings. (My error log is full of error messages related to user2role2object_rs)
So, my question is this:
Is it absolutely safe to remove the tables:
user2role2object_rs
user2groups_rs
role_scope_rs
groups_rs
http://wordpress.org/extend/plugins/role-scoper/
it was. But Role Scoper still exists inside a lot of tables in the database. The problem now is to identify, empty and delete the actual rows. Dangerous work.
...and it was hard to find them, but I did, and I deleted them all. With success.