Display size problem when going through vga splitter

[pballer2oo7]

I have a Vizio VO42OE tv with VGA input and two Acer A221HQV monitors.

I have the resolution on my laptop VGA out set to 1920x1080. When I plug the Vizio TV into the VGA output it fills the screen perfectly, everything looks wonderful. The problem: when I plug a StarTech ST128L 8-way VGA splitter/amplifier splitter into the VGA output of my laptop, then plug the Vizio and the Acers into the splitter, the Acers fill up perfect, but the Vizio has black bars along both SIDES. Vertically the Vizio displays and fills correctly.

I've played with the Vizio's options, tried horizontal stretch and position. I cannot get it look right. What about going through a splitter is causing this horizontal fill problem?