I un-neighbored a few friends that had not been active since December to make room for active friends to become neighbors. Always before the friend I removed from being a neighbor stayed on the page and showed white instead of blue, but this time they disappeared off my "My Neighbor" page. I expect some of these to play again and hoped to reinstate them as neighbors once the quantity allowed is increased. I still show some friend farmers who are not yet neighbors. I have cleared memcache several times since this happened with no improvement (always try that just in case
. Someone else I know has had this happen as well.