Season 3 of Gilligan's Island,some episodes begin with a bit of the show before the theme song comes on,does anyone know if the ones that didn't originally have it, also had them but has been lost or whatever and was it the same for Season 1 and 2.

The short opening to set the general story before the opening credits is called a "teaser" and they were only done on certain episodes of Season 3. Teasers were becoming popular about that time and more and more shows were shifting their formats to include them. :)

It certainly gave the guys who wrote suspensful, surprising, or ominous incidental music a great place to end on a loud chord! :lol:

Green Acres also switched to having a tag scene before the credits during it's later years too.

The earliest show that I remember having a teaser was Dark Shadows, but it was absolutely necessary for them as they had 5 cliffhangers a week!