Since you mentioned watching the Bolton DVD I assume you are looking at this from a strength / powerlifting perspective as in you want to be able to lift more weight. Not a bodybuilding perspective where you are using the dead lift as tool to build back thickness/hams/etc.
You need to figure out what you're weakness is, it could be any number of things:
1) poor-starting position:
is the bar too far over your foot/toes when you start? if so this throws you too far forward and makes you weak of the floor. Are your hips too high? if so this eliminates leg drive and makes you weak off the floor. Are your hips too low? if so this puts you in a bio-mechanically disadvantageous position, and you are weak off the floow.
2) poor quad strength / leg drive strength:
if you dont have the strength to leg drive the bar off the floor, you'll be weak off the floor. Do you feel like the weight wont budge if you try to push with your legs, but that if you shift the weight to your upper back you can get it moving? if so, you need to adress this weekness (front squats, front squats to a low box, close stance SSB squats w/ and w/o a box, leg presses with a DL stance, speed pulls, deficit pulls, etc...)
3) poor low back / ab strength:
Can you not hold a low back arch? if this is a weakness you wont be able to transfer your leg drive towards breaking the bar from the floor. If you lose your arch b/c you cant hold it this is a sign that this area is weak. If you lose your arch only b/c you can budge it with your legs and by rounding your low back and then re-arching you can get the weight then this is actually a strength that you're using to overcome pt #2.... to overcome this you need low back / ab work (hypers, reverse hypers, good mornings, weighted sit ups, etc...)
4) upper back strength:
Similar to #3 rounding of the upper back can either be a sign of strength or a weakness... you can adress with rack pulls, shrugs, rounded back good mornings, seated good mornings, anythign with the SSB. overload work (bands and chains) etcc
No matter what your weakness is absolutely pause each and every rep on the floor. Going touch and go or not all the way down is building nothing but your ego, you are doing what you're good at, and further exacerbating your strength imbalance. Attack your weaknesses until something else becomes a weakness and then attack that. Its a moving target, but a chain is only as strong as its weakest link....