Hi Claire and Mrs. Essex, et al --
I got a giggle out of the two year thread bit. However, I guess the answers are still applicable.
The dress size thing really depends a lot not just on weight, but as those of you with curves know bust and hips -- and even more so (I think) height and overall build. I have a friend who is 5'11" and she has to lose amost 2 stone to drop one size! I am not quite 5'4" and two stone would be four sizes for me!
MinnieMel