A friend has an Acer Laptop running Windows 7. When she presses the down arrow while in a browser (both IE and FF) it acts like the back button. I checked sticky keys and they are not on. She said that it started around the time that she installed a multidesktop system Yod. But, she uninstalled it and the problem still was occurring. One other weird thing is the fact that I worked on it a while and the problem was there, but then for no apparent reason it started working properly again.
PS she mentioned some other key problems, but I am not sure exactly what all they were.