It's all a question of software. And software in closed systems is rarely good and is practically never updated, so you're at their mercy.
Even if you found a solution now your next TV will do it differently, so you'll have to find a solution again.
If you've updated your TV's firmware and that's still the behavior, the only things I can think of are :
* Come up with some script on your PC to preprocess photos before sending them to the TV.
* Try to use your TV file browser to access photo directories on your PC, instead of pushing them to the TV. Maybe the TV uses a different photo viewer for that scenario, and maybe it works better.