My clients has recently had a problem with spam posts being added to their blog, under various usernames. The users have been deleted, but Wordpress is not able to remove the posts from the trash. Using the 'Empty Trash' button does not work either. Removing directly from the database appears to work, but as there are 4000+ entries this would take a long time.
This is Wordpress v3.4.1 and has been upgraded recently.
Can anybody help?