When I select "Enqueue files in playlist when in one instance mode" in the preferences and click "Save", the setting reverts back to off each time I start VLC again. Therefore this option appears unusable.
This is a regression - it worked in 0.8.6*.
The problem appears on both 0.9.2 and 0.9.4 for me, and on all three computers (Windows XP based) I have installed it on. On each one I set it up for one instance mode, and it does not remember the "Enqueue files" setting.
Cheers