For the past few months, I've had this very weird problem. Any time I'm online, what looks like a big cursor (as if I'm in a writing program or typing in a text field) will appear in random places on any webpage. The cursor flashes, can be different sizes, and comes and goes randomly. Sometimes it's almost three-quarters the height of the webpage; sometimes it's small. I mentioned it to a computer-savvy friend who suggested that the computer might be infected with a virus. I have Avira, but apparently it's not catching this virus, if that's what it is. How do I know whether Firefox's anti-virus program is enabled, and do you think it can solve my "cursor" issue?? Help!