when opening a .pptx file from email, etc, the presentation opens in 'read only' mode. In that mode, I don't seem to be able to navigate the document with normal keyboard actions like "page down" and "page up". This is annoying! I usually end up clicking "edit" just to be able to move around freely.

(Actually this bug reflects a general worsening of keyboard interface design in recent versions of LO. Key bindings are just progressively getting muddled and duplicated. It would be really great if there could be a general effort to test keyboard usability with LO. People with RSI etc need to be able to comfortably use both keyboard or mouse.)