When starting the program, effective sort order seems to be Filename. List-Box does correctly display that for a new Search, but for Filter and Browse it will display whatever value was used in the previous invocation of the program. Re-selecting whatever is displayed in the list-box will change the effective sort order.
I typically sort by caption time, and that is what is displayed in the list-box, even though the effective sort is filename.
Hans-Jørgen