First I will thanks everyone that di replay my post (Lonkero and sealeopard)

I did find out my problem when I tried out everything you said, and had to do a lot of test and fail.

The soulution to my problem was (Running win NT4.0 server)

Group "DeskTop" was loacl groupe and not global,
then where the old KIX did find the users the new one didn't, so the soulution was to make DeskTop group into a global group and then the script went on as it did before the upgrade of KIX.