I'm a GNOME user, so this may just be me.
I am completely unable to get autorun to work in KDE.
It does not mount the DVD, it does not run the autorun script on the DVD.
When the user logs in, the autorun thing bounces - but then it stops bouncing, and that's all - media is not even mounted.
I should add that it works flawlessly in GNOME when I enable autorun there.