Thanks for the uber-
alerts, but of course that's not one of the two missing scenes I'll go to my grave insisting were in the original. (And once I go to my grave, they will be erased from all recorded and imaginary history).
That's a scene that was never in the film, and not even one of the more interesting ones. Close Encounters is really marvelous for what was judiciously left on the editing room floor. In particular, Spielberg seems to have filmed every second of Roy Neary's travels on the night of the electrical blackout. That he edited this down to one of cinema's most arresting segments is quite a feat.
(My favorite deleted scene is a garden party that the Nearys have the afternoon after Roy's close encounter. It's a total hoot. Great DVD extra.)