I used to struggle to defrost apps on KitKat!
I did so much of what has been described with packages.xml, though I did not try other apps to defrost.
I randomly tried something in TiBu that fixed the problem for me instantly.
In the menu I selected "reload apps list" - it then defrosted the problem app just like normal. I couldn't believe it, after spending so much time trying to tweak that packages.xml file (and whatever else I had tried).
I hope this works for someone else having defrost troubles.
Best of luck!