When Luke is upside down in the Wampa cave, and fails to reach for the lightsaber, I remember then hearing Obi Wan's voice instructing Luke to "use the Force". After hearing this, Luke then reaches out and tries to grab the saber using the force.
The version I saw was most likely a re-release in 1981 or 82, 35mm print. Now it could be possible that I'm simply remember something from the storybook or record or whatever. But heres an instance where I could swear I heard that Obi Wan dialog, and have been looking for it ever since in all the different mixes Lucasfilm has released since.
Anyone else hear of this bit of dialog in any of the released versions?