The download goes OK but the message box where you move the Firefox symbol to the Application logo does not come up automatically. I go to my desktop and click on the icon for Firefox 4.0 .dmg At this point one of two things occur, either there is a circle and slash across the Firefox log and I cannot do anything, or the circle and slash is not there and I can move the Firefox logo to the application logo. It begins to run, I select "replace" existing Firefox and it runs a bit longer. Then it say 1 of 2 files. no enough KB