I don't have a lot of details right here to be able to tell you precisely what it is. So perhaps you can just double check your setup. Here's a guide you can follow: http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?idx=154745&modelname=UN65D8000XF&modelcode=UN65D8000XFXZA
I am using the display as a computer screen via DVI-HDMI into the HDMI(dvi) port on the TV. I can get it to display the entire computer screen by choosing screen fit in the screen adjustment menu, but after about 15 minutes or so, it reverts back to a zoomed output and I have to manually go back to adjust it via the picture menu. Thoughts?