I've attached a picture of a black box that pops up on a clients Macbook when he opens Firefox. Running 10.6.8. I have disabled all login items, I can find no extensions that would account for this.
This does not happen in Safari, I can't find any applications that look unusual. The box lists several items and grows longer, then after 15 seconds or so goes away. I cannot make it go away on my own.
I don't know what it is. Help?