Don, I know bugger all about that model of saw, but it sounds to me like the blade has a lot of backward and forward motion. I don't know if there is a way of adjusting this on a Wen. Move the blade to it's lowest point and place a piece of wood or a rule against the back of it, then move the blade to it's highest point and see how much the wood moved or the gap between it and the blade.
That's about all I have to offer, sorry mate. Hope you get it sorted soon