I have a site running Drupal 6. I was having performance problems so I turned on Drupal's built in "normal" level of caching performance -- which claims to not have any side effects.
Since I enabled this feature (about 3 days ago) I have users reporting that they are not seeing the latest content -- specifically the latest posts on the front page appear to be from several days ago. I believe this is happening both for logged in users, and anonymous users. I have not yet seen it happen as either a logged in user or an anonymous user.
What might be causing this and what steps can I take to troubleshoot it?