I have a hp a420n. I bought a radeon 9600 se when I bought the machine, as well as a logitech mx500 mouse. Never had issues with it. Two years later the video card died(about a month ago), and I bought a x800 pro by Asus. Now I have issues with the card and the mouse operating together. If I install the ati drivers for the card and the logitech drivers for the mouse, the mouse will randomly jerk down to the bottom of the screen. This is the computer I use at home, and when my son plays videogames on it, it does the same thing. Later I tried uninstalled the mouse drivers and using plug and play by windows. This has proven to be most effective, yet still has issues. The cursor will "stick" in places, mostly the right hand side of the monitor, and will randomly move when the mouse is sitting still. I've tried other combinations including third party drivers for the videocard (Omega Drivers) and still had issues. The windows drivers for the video card have the same issues. Any help is appreciated.