Have a section of pages wher there are not enough adwords to serve, so get charity ads about 80% of the time. Have emailed google to see if they can improve it for me. Other issue here is that the page name is not changing on your site so "mediabot" will not revisit. One of the intial visits have set the ads for you. Changing the page name will get the "bot" out to have a look. When adding adsense to new pages seems to get it out to index quickly. Just some thoughts on this.