<A target="_blank" href="http://www.curiousmitch.com/2011/03/notes-8-5-2-installer-does-not-always-update-rcplauncher-exe/">Mitch Cohen discovered that an upgrade from Notes 8.0.2 to 8.5.2 may not replace rcplauncher</A>. He's provided a link to the Technote in case you're experiencing problems.