I enabled "System tray icon" and "Window title" plugins in Parole 0.2.0.6 (XFCE 4.8, Xubuntu 11.10), but they don't work. No icon appears in the system tray and the title is not changed. Here's the output when I run Parole on a terminal: $ parole (parole:3246): GLib-GObject-WARNING **: cannot register existing type `ParoleProviderPlugin' (parole:3246): GLib-GObject-CRITICAL **: g_type_add_interface_dynamic: assertion `g_type_parent (interface_type) == G_TYPE_INTERFACE' failed (parole:3246): GLib-GObject-WARNING **: invalid cast from `TrayProvider' to `ParoleProviderPlugin' ** (parole:3246): CRITICAL **: parole_provider_plugin_set_player: assertion `PAROLE_IS_PROVIDER_PLUGIN (provider)' failed (parole:3246): window_title-DEBUG: Init (parole:3246): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed (parole:3246): window_title-DEBUG: Finalized $
Please try to confirm this bug with git-master. I tested the tray-plugin in Xubuntu 12.04 with Xfce4.10 and it works great. (The window-title plugin has been merged into the core and made default behavior.)
As much of Parole has been reworked with the 0.3.0 release, I'd like to ask you to try again and if you experience any problems with the plugins report a new bug. Closing this one in the meantime.