That's caused by an ad I think.
Problem is, the site runs on ads... adding Adblock is like not investing into your company's stocks.Very likely true, but should be reported nonetheless so the site owners can deal with the ads. Having said that:
Firefox with Adblock+, Adblock Element Remover, Noscript, and Ghostery and this is a non-issue.
just get LB to report the ad...Yes well unfortunately if ads didn't have the problem reported above there wouldn't be a need to block them.