Akismet – can’t see icon on site

My post of 8 hrs ago was answered (I think) in another posting, which stated that API keys can be used on multiple accounts. Is this true? I can’t be sure, because after entering the API key from my other account in the field on the Akismet configuration screen, nothing seems to happen when I click on the “Update API key” button, and I still don’t see the Akismet icon on my sight. The yellow message banner saying I needed my API key to activate Akismet is now gone, however.