RE: Squatting back problem
well in waiting for your reply, if your think its due to strength in your back muscles.... think of trying lower weight without a belt? this would help strengthen your core strength and maybe you would have better control? just one tip I can think of off the top of my head. also i know you might think you have propper form but try videotaping yourself or asking someone who knows what they are doing to watchyou, just for another referance.
475lbs x3 - deadlift (belt)
420lbs x3 - squat (belt)
315lbs x2 - bench(wrist wraps) - Prefer dips/pressing
Joined the army July 14th 04, damn their ways of exercising, comunist bastards =(