1.- If you have verified that you have
installed it to the correct folder, and that
folder is active in Live's Preferences →
Plug-ins, then disable the plug-in folder
and re-enable it.
2.- Wait for the plug-in scanning to
complete, then check the browser list again.
Alternatively, perform a full rescan of all
installed plug-ins by holding ALT/Option and
pressing "Rescan Plug-Ins".