So I've been witnessing a few odd dings and dats in the wpmu dashboard lately.
For Example:
1) going to users and clicking on Registered to sort the table as such throws out this error:
WordPress database error: [Unknown column 'registered' in 'order clause']
SELECT * FROM wp_users ORDER BY registered ASC LIMIT 0, 30
2) Sometimes selecting multiple blogs and pressing delete throws an error (which I can't reproduce right now since I have no blogs to delete)