As the person above me said, that is your problem. It doesn't matter too much how the liner fits, it is all about the shell.
You are falling out of your boots because they do not fit.
Boots should not fit "too tight" or "too loose", they should fit like a sock. They should put uniform pressure around your whole foot, and not just because the liner is poofy. It sounds to me like your dalbellos were the better bet for you.
That being said, I am glad that you know what a shell fit is and that you performed one. I give you 4 points for that.