Firefox Acting Weird

shafe88

Distinguished
Jul 6, 2010
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Why does my firefox stop responding for about 1-2sec with a white screen with 2 blue squares, both in the middle of the screen, one almost at the top and one almost at the bottom. The blue squares does writing or something, but cant tell.
 
This sounds like an addon that you installed in firefox as I've never noticed this behavior. Does it do it with all sites or just certain ones?
 
I don't know what happened, but after I closed most of my tabs, fire fox still stops working, just that firefox is black now instead of the white with the two blue boxes.