Advertisement appearing in wrong place
Macbook pro running OSX 10.7.5
Every so often an advertisement for concrete paving (it's one that sometimes appears at the bottom of the page) appears at the top left corner of the forums list. It's not as big as when it appears at the bottom, but is big enough to block out the topic etc.
I can stop it happening for a while by clearing all cookies, but I wonder if this happens to anyone else, and what causes it. It seems to be only this ad, and only on PPRuNe.