Backboard Out of Bounds

[Brian S]

One last topic from games I did last weekend:

Ball hits the rim, bounces straight up and lands on the top edge of the square backboard, then bounces back down onto the rim.

Is the ball landing on the top edge of the backboard out of bounds? I know that the ball can't pass over a square board, but what is the ruling when the ball lands on top of the board and bounces back into play without passing over the board?