I started Jillians program on March 22nd (yes, i remember the date exactly!) and i'm down 40.9 pounds (18 kilos). And i agree with ledom, it's not a race and we all have times where we may not be as disciplined as we should have been. Sure, i would have liked to have lost more, but i'm very happy with my progress and the results. It all just takes time, i didn't put on the weight overnight, so i can't expect it to come off overnight.
My diet's pretty good all of the time and i get in nearly all of my workouts, i just sometimes have a few weeks were i do everything right and i may not lose, but that's ok, i know the weight will come off, and i've finally found a program that works for me.