Thanks for your "slightly disrespectful" comment thirdnalga. I am not some novice complaining that lifting weights makes me sore, I have been training consistantly for more than 20 years but have never experienced lower back soreness/fatigue on such a regular basis. I have experienced training soreness thousands of times and trained through it and I have also trained while ignoring warning signs and ended up injured.
What I am asking is does lower back fatigue pre-dispose me to injury? or because I'm more than 30lbs past my old deadlift PR, should I expect this each time I train now as each week I am doing more than I have ever done before?. The last thing I want to do is "nut up" as you say and then miss months of training rehabbing an injury.