In the Notebook column in Mac version 10.4.4, using Up/Down keys will move the selection up/down as expected, but does NOT refresh the visible note in the pane to the right.
Contrast with selection via mouse click updates the "Note" in the right pane.
Using keyboard selection, you CAN press ENTER to refresh the note being viewed, but prior to this the UI is miss-representing the combination of selected note and note on view. This is particularly troublesome combined with the number of copies of notes the new version sometimes creates which need reviewing to find the most up to date version whilst deleting redundant copies.
This issue apparently appears in the PC version too: