I occasionally get 4x8 sheets of plywood for projects, and I've heard that I should never use the rip fence for cross cuts because the peice that is being cut can get trapped in between the sawblade and the rip fence and cause kickback.
I can't see a way to avoid using it though, as my miter gauge doesn't have enough track to travel all the way to the base of the board. Should I use the rip fence to cross cut these types of boards, or is this mroe of a task for something like a circular saw?