Hey there.

I've just noticed some weird things happening in FF3 for the last day or so.  I can be browsing virtually any website, when suddenly what would usually appear as a popup ad will appear - upside down - at the bottom of my browser window.  If i scroll down far enough so that the ad disappears off screen, then scroll back, it does not return for another ten-twenty minutes or so.  It's very odd.  Bear in mind that these aren't strictly pop-up ads...they're the sort that appear with media in them (videos on stuff etc).  I've got a few extensions installed but i've taken them all off to test the issue and it still happens.  so i've put them back on.  screenshots are to follow but in the meantime does anyone know what might be happening here?