> If cursor is focused in inputbox of find or replace strip dialog, and user presses Ctrl+Z, then Undo is executed in editor text pane instead on action in focused inputbox. I don't know of application that does the same (i.e. undo is executed on inputbox actions if supported or not at all if not supported, AFAIK), and have no idea if it's known issue, bug, or feature, but thought to comment on it as it's unexpected behaviour IMHO
For replace, its quite common to make a mistake and want to undo the effects in the document. Part of the reason for using strips was to integrate more closely with the edit pane. I suppose its a bit too confusing though.