Windows Vista user profiles

I have a roaming user profile for one of the users, when this user tries to log on to any Vista machine, after the welcome screen it logs off the user right away. The same user can log on successfully to any XP machine.

On the Server a folder with v2 extension is also created on the server

I also made a copy of this user account in active directory, and the new copied user logs on succesfully onto any Vista machine.

I am not sure what is causing this behaviour,
any suggestions??