Another discovered detail - While in a folder, after clicking the "move to next unread" button thro

Another discovered detail - While in a folder, after clicking the "move to next unread" button through each unread message till I reach the last unread, message, if I then click on an already read message in the same folder, rather than clicking the "move to next unread message" button, then, the last unread message is marked read. SO, it's only when I click to continue to the next unread message using the menu button that I leave behind a message still marked unread, even though I'd just displayed it. To reiterate, only the last unread message in any given folder exhibits this issue.