 CONT: In several shots of the Enterprise throughout, we plainly see  a pair of phaser turrets just below "U.S.S. Enterprise" on top of  the saucer section. As Kirk, Spock, McCoy, Decker and Ilia emerge  from the saucer section en route to their VGer encounter, the  phaser turrets are completely missing. Not only this, the slope of  the hull is far too steep. (this is fixed on the Directors Edition  DVD).