The muine dependency on || ( =sys-apps/dbus-0.61* =sys-apps/dbus-0.62* ) (for dbus-sharp bindings) is somewhat unsatisfactory. Raised upstream at http://bugzilla.gnome.org/show_bug.cgi?id=392142 ; an alternative would be to get NDesk DBusSharp working (see bug 159793) but I've had trouble getting that route to work.
Fixed in the new muine-0.8.7 which is in portage as of today.