This has been mentioned before.
The adverts are automatically selected by Google using some kind of ranking algorithm that notes the frequency of appearances of certain "trigger" words in the page contents.
Admin has tweaked it to avoid certain "misunderstandings" but in general there is not much we can do about it.
that from time to time shows as a "pop-up" style insert that wobbles around the screen.
That doesn't sound like the usual kind of advert we have here. Could you please include a screen shot of that part of the screen, just in case ...
And just a thought: are you using AOL or Yahoo, where a part of the screen is used for
their adverts.
Bob