The overhanging advert banner

The one that appears over the top of the title, then follows you as you scroll down a page.

I realise the site has to make money, but it's kind of a bit... in the way. Especially when you're trying to edit pages and it appears on every single one. Is there any way to get it to stop?

Also, for the last few weeks I've had to delete cookies to get onto this message board - no other sites. Any idea why?