I don't know much about computers. I have OSx10.7 and suddenly for no reason when i click on an icon for a document on my desktop, the firefox that I had open disappears. I am unable to have both the firefox window and the other document window open at the same time. I think this has something to do with different desktops but I never puposely enabled anything like this. I just want to have firefox and the document open side by side the way I always have. Please help! Thank you