Well, I saw the article about the newer nVidia version of Impulse, so I downloaded it and installed it on Windows XP.  I rebooted, and now there is no icon for it in my system tray.  So I uninstalled that version with Add/Remove Programs, deleted the Impulse folder, ran my registry cleaner, rebooted and installed the version I had of Impulse prior to that.  I still have no icon in the stem tray.  Any ideas?