In the configuration of Eclipse (config.ini) you must manually start the dropins because it is not autostarted by the Aptana Studio RCP application definition. Note: In the standard Eclipse Distro it is started.
osgi.bundles=org.eclipse.equinox.p2.reconciler.dropins@2:start
Once added, the configuration file Aptana->About->Installation Details->Configuration should now have this listed plugin as "Active" rather than "Resolved"
org.eclipse.equinox.p2.reconciler.dropins (1.1.100.v20110815-1419) "Equinox Provisioning Drop-in" [Active]