When toggling split-view mode on and off, some menu actions don't update their sensitivity accordingly.

For example:

- select a file
- check that the "{Copy|Move} to other pane" menu items are disabled (ok)
- start split-view mode
- check that the "{Copy|Move} to other pane" menu items are enabled (ok)
- end split-view mode
- check that the "{Copy|Move} to other pane" menu items are disabled _without changing the selection first_ (not-ok - they are still enabled)