With the selection tool selected and the comments pane open, you should be able to click and type anywhere in your PDF, and the relevant text edit tool will be applied (strikethrough, replace, insert). This is a great timesaver. On my Mac, though, this works until I press one of the 'problem' keys – such as e, y, i, d, h, j – at which point no mark-up appears and my keyboard is disabled (including the arrow keys) until I close Acrobat and reopen it.
Does anyone else have this problem or know how to fix this bug? It doesn't seem to make a difference whether or not 'single-key accelerators' are enabled, and I don't think I have these keys assigned as hot keys in any other programs.