I have had this happen to me a few different times and I am not sure what the problem is. I will be working on my Macbook Pro (Tiger - OSX) and all of a sudden, the functions will change. For example, everything will scroll to the top, and if I use the mouse, touchpad, or tablet to scroll it down, it will immediately scroll back up again. This is true across applications, safari, finder, etc. In photoshop, it will automatically zoom all the way into my photo and I can zoom it out again by selecting "fit to screen", but as soon as the cursor goes over the photo, it will immediately zoom in again. Also, the tool buttons do different things. Also, on my desktop, I tried to drag a folder, and instead of dragging, it made a copy. Also, when I try to quit using cmd-Q, it won't work, I have to do it from the file menu. If I shut down and restart, all is back to normal again. I am assuming that I am hitting some combination of keys that puts it into a different mode, but I have no idea what that may be (and honestly, sometimes, I don't think I was even using the keyboard when it happens). Also, it has happened on my imac running Leopard, so it's not specific to this computer. Help! Thanks!!