Does ReactiveUI leak subscriptions?

Question

I've looked at the examples of ReactiveUi from the blogs and I am left wondering if ReactiveUI has some sort of subscription management facility underneath or are the examples ignoring the fact that they might leak subscriptions?

Any time I call a method in ReactiveUi that results in an IDisposable, do I need to hold onto that reference and track it myself? Also does this mean my ViewModels need to be disposable, this seems difficult since we don't really know when the connected "Views" go away (i.e. if my ViewModel reflects items in a data grid) in WPF so there seems to be no appropriate place to call dispose.