Voice and Pic sync prob.

I recently was sent a new cable modem and since, it seems, as though the picture and voice get out of sync. Woke up this morning with Fox News on and it was WAY out of sync. Any other folks having this prob? I have and older cable box at the TV. When it gets out of sync I turn the box of then on and all is right with the world.....for a while. Kind of bugs me.

Any solutions?