Hi all,
I have been working on Windows 7 and never found any problems with list boxes in dialogs, until I ran the same script on another machine that had Windows 8.1 installed. None of the list items appears in the list box there and there is no way to work around the issue. I have submitted this bug and will report here if there is a solution. It might take a patch to get this nasty bug solved. I did not test it in any of the other Adobe application that use ExtendScript with the same ScriptUI.
Just be aware that list boxes will not work on Windows 8.1 for the time being.
Kind regards
Jang