You don't have as much weight to lose, which could be why you didn't lose as much. Usually people who weigh more are the ones who see the dramatic lb loss in Phase 1.
It also could be like the other posters said, that you're eating too little. You've got to eat enough to keep that metabolism going so it can burn more calories and thus more pounds. Are you eating your snacks?
Are you having some reduced fat or fat free dairy? Throw in some fat free milk for a beverage.
Hope this helps.