Windows 7: UAC file virtualization not working

Hi all,
I'm having a little trouble with a game just installed. I have a game that's quite old and writes its savegames to the program folder. I've installed it in a custom folder (NOT in the default program files) and gave admins full control and users read and execute permissions.
UAC works fine in requesting elevation when I do file management there, but when I try to save a play within the game, I would expect the save to be virtualized into virtual store and the game thinking that it succeeded. But instead it just throws an error and fails without saving anything. If I command the game to save to the root C directory, it works (and the save is actually put into virtualstore).

Anyone knows how to fix that? My intention is to not give users write permissions into the game folder to allow savegames, but rely on virtualization to throw them into each profile.
Thanks!