I have a 1995 chevy silverado 4wd, it jumps when I go to stop (rotors warped).?

[deerscoper]

But my question is, when Iam at a standing stop, I accelerate to about 40-45mph and it jumps at that time and stops when I get to about 49-50mph. Is it my calipers sticking or what? But its fine until I get to around 40-45mph then it starts and just like that it quits.