Page Up/Page Down appear to do nothing for me in Preview Mode.

Steps to recreate:

  1. Press 'x'; observe 'PREVIEW MODE' text appears in bottom-left Screen Panel
  2. Press PgUp/PgDn


The help text immediately below "PREVIEW MODE" says that PgUp/PgDn "Scroll through the hotkey list"

What else do I need to do to bring up the hotkey list?