I asked the same question a couple of weeks ago and someone responded with a good try at helping me. But even with running some of the exe files as administrator, I got the same results as everyone else. I am able to run the program under Vista, but it doesn't save the sessions I modified or added.
I've been adding new sessions by running Trainz on an XP Home computer. After making and saving the changes to that computer, I burn a DVD of the modified Auran program folder. Then I delete the program folder on the Vista computer and copy the revised Auran folder to C:\Program Files. Kind of a long way around, but it works.
Hope this helps.
Art
(whyfly)