Comment 1 for bug 896424

I saw similar errors. If you install Empathy, pulling in all of its Telepathy requirements, I think you’ll find that the Telepathy-related messages go away. Whether that’s a good thing or not I don’t know (I don’t use/want Telepathy), but I think it’s fair to conclude that the error messages are due to the GNOME Shell expecting Telepathy to be present, and reacting less than gracefully when the dependency is unmet, as in Mint’s default, Telepathy-less install.

I’m still left with the assertion failure:

Window manager warning: Log level 8: shell_tray_manager_manage_stage: assertion `manager->priv->stage == NULL' failed
      JS LOG: GNOME Shell started at Sun Nov 27 2011 22:59:35 GMT-0800 (PST)