Pop-under Ads from Digg?

Am I the only person getting pop-under ads from Digg? I don’t think it’s malware (it’s on my Mac). I don’t think it’s another site (I’ve only got Gmail open).

I’m not getting it on every page load, but it’s definitely happening. I’m guessing that it’s being caused by a rogue ad that’s getting brought it by the many ad services Digg uses.

I’ve only been getting it when I leave Digg up for a while. Lately, Digg pages never seem to complete loading–Firefox just spins and spins trying to load the last couple of elements of the page. I wonder if the two are correlated. Of course, after getting two ads in about 15 minutes, I haven’t gotten another one since.