Are you playing on a different computer than the one you disabled ads on?
If so, try logging out, and in again!
Technical explanation: Your current ad preferences are stored with your logged in session. The session is updated when you log in.
I’d like to see Community Ads, how can I do that?
Under Options, there’s an option to show community ads, even if you’ve disabled regular ads.
If you can't find your problem in the knowledge base, please submit a bug report.