How to clear Data Failure Detected alert from Database Control home page

We recently received a critical alert on the OEM database Control (11g) home page, Category=Data failure, Name= Data Failure Detected, Message=Checker run found 2 new persistent data failures.  From the alert log, I determined this was related to some DBFs that were removed.  I recovered the DBFs and restarted the database and all looks fine.  Oracle recovery advisor show no errors.  I ran the DB Structure Integirty Check and it found no errors.  So, I want to remove the alter from the home page.  I went to the alert log errors page and selected the alert, then pressed clear.  I