Without specific makes/models of all involved, it's no more than guesses. Also provide some title examples of DVD & BD discs that give you issues.
(Do you have the latest firmware for all devices, btw?)
I have an older Mitsubishi 60in tv and a sony blu-ray player. I also have 3rd party 3d adapter which sits beneath the tv.
The problem is sometimes the 3D movies work great, and at other times I get a double picture (one below the other about half a screen).
This doesn't seem to be DVD related as a DVD that plays well today may not tomorrow.
Also, the blu-ray plays non-3D discs, and the same problem exists with them - in the non-3D mode of course.
Any ideas would be appreciated. I've a feeling it is operator error, but have been unable to pin it down.
Thanks in advance.