My boss has an iMac and he goes to a site and it says blocked plugin. This is for flash. It tells him to update. He does this and installs the new update for flash and the site plays the video fine. Then the next week it happens again. And he updates and installs flash and it works again. This happens about 10 times a month. What needs to be changed for this to work? Flash is set to install auto updates so I don't know what is doing this.