In a nut shell, if you have a TreeView List Box with an Expression and also sort by this Expression, you may get unintended results. Specifically, the List Box will not dynamically re-sort after applying selections. However, the List Box will sort correctly if you uncheck the Expression sort, click Apply, and then recheck the Expression sort within the List Box Properties.
I'll let the attached example demonstrate the situation, but will explain here further if needed.
I'm in the process of formally communicating with QlikTech on this and will post updates as I get them.
Qlikview Version 10.00.9055.7 SR3 64-bit Edition (x64)