I understand how you might feel disappointed as it seems like a lot of sacrifice for not much payback, but I think that it usually works out that if you lose a smaller amount then the next weigh-in is usually more substantial.
Really thats 1/4 stone gone and a good weight-loss!! As caroline g said, its more than you'd get on a 'normal' weight loss plan, and anything off is a step in the right direction.
How has you water intake been? I think this can affect your loss, perhaps you aren't having enough?
Best of luck and stick at it!