Firefox froze on me when I tried to save my progress in Super Mario Crossover. So I force quit it, after waiting for an hour for it to try and fix itself. I had about 20 tabs open, maybe slight more. Most were links to an academic article website, so nothing too taxing I don't think. Well, once it closed I tried to reopen it. When I did, I was given the prompt : "Close Firefox A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Well, I don't have another copy open. How do I go about solving this problem. == This happened == Just once or twice == This just happened == == User Agent == Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_2; en-us) AppleWebKit/531.22.7 (KHTML, like Gecko) Version/4.0.5 Safari/531.22.7