[Plugin: Advertising Manager] Clean Install Needed

I need to uninstall and reinstall advertising manager clean. When I do it through the admin GUI or by deleting files from the plugins directory, the old ads still appear. If I delete the old ads via the admin interface, they come back. I can’t add new ads. I always get the message “Advertising Manager has been upgraded from your Adsense manager”. It will not go away unless I delete the files, yet when I reinstall the plugin, that message and the ads reappear. How can I clean out the install and start over?

Thanks.