Unfortunately, this is one of those things that's person to person dependent. Do you mind me asking how long you've had this TV and was this the first time you've tried this feature?
I can't adjust the 3D settings for my Samsung UN46D6000. I followed the instructions, but when I turn on the 3D through the remote control (and sync the glasses with the tv), the image is duplicated much more than expected. As far as I know, the image duplication is intended, but in this case it does in a very wide range, almost spliting the screen in two frames in a "side-by-side" comparison.
I've done the test with a 3D Blu-ray disc, in a 3D Blu-ray player, of course. Does anyone know what could this be?