I have the same annoying problem. I really dislike TVPlus, and this quirk is making me dislike my Samsung to the point that I doubt I will get another Samsung "Smart tv"...
I have HULU LIVE on, and sooner or later crappy TVPlus takes over, normally right at the end of an hour long show, making me miss the ending in some cases. I thought maye HULU LIVE was just failing, but it never has this problem on my VIZIO. HULU LIVE works flawlessly on the VIZIO, so I am ruling out HULU and blaming SAMSUNG.
I have a UN55KU6300 TV software version 1233. They tell me there is an update to to the new firmware verion, but the TV isnt presenting the ability to upgrade or self-diagnose (they are both greyed out and state "NOT AVAILABLE"..), so I am advised I have to screw around with a download to a thumb drive and manually update it. The hell with that noise!! I don't feel like pulling my TV out of a console cubby hole to stick a friggin thumb drive into a USB port and maybe have a better result.
Prognosis: TVPLUS sucks and it is beginning to make SAMSUNG suck.