I had similar problems with this program. If you are following the program the way its written, you are performing a reset, not a deload. A reset is when you decrease the weight that you are lifting, usually by about 10%, then work back up. In Starting Strength, it is implied that reseting will help you get past some of your first stall points.
But reseting never helped me at all. Like you, I reset several times and still stalled at the same point. I have since changed over to a program with scheduled deloads, and have been able to progress past my stall points. However, you can do deloads while still following SS. During a deload, you decrease the volume of your lift while keeping the weight the same, usually by reducing the number of reps you do. So if you are on a 3x5 program, you would deload by keeping the weight the same and doing it like 3x3 for a day. Then you would progress normally on the next day. When deload, you want to do it for ALL of your main lifts that day (Press/Bench Press, Squat, and Deadlift), and also for both your A and B workout days. A good rule of thumb is to deload every 6-8 workouts, IIRC, as per Pavel in one of his books.
Some technique changes that have greatly improved my deadlifts are using a mixed grip instead of double overhand, and focusing on dropping the hips and throwing the head back & chest up as soon as the bar leaves the floor. Keep your weight on your heels, focus on trying to pull the bar backwards into you.