I could not find this mentioned here earlier:
Click on a row in a multicolumn table and you can navigate up and down the list with the arrow keys...fine. Now make a button e.g. that fires a value signalling event for the multicolumn list after you have clicked the cell (set the value to a row different than the one you manually click on)...then programmatically set the key focus back to the list.
Now let's do the test again: Click on a row in the multicolumn listbox, then click the button to fire the value change event and key focus...The list is now in focus so use the arrow keys to move to another row...Result: The listbox will start the move from where you last clicked it - not at the currently selected row(!).
The arrow scrolling should have checked the current value of the listbox when it calculated the next position.
In my case I'm giving the users an option to sort the list - and then continue to navigate. The currently selected row is updated programmatically so that the content that was selected prior to the sort is still selected afterwards...and the focus is then set back so that the user is free to start navigation immediately after the sort...and that is when the keyboard navigation fails in this manner.
