I have been struggling giving access to new users, some of them works fine but some of them don't. We do have a certain security level so all users also has to be granted access from our IS helpdesk. They say the users are on the correct list. What can then be the problem?
In my work we use AD groups, so every time we add a new user to a group we have the same problem, and it is always because the user didn't log off in order for the changes to be applied at network level.
As Peter mentioned it would be easier for us if you could share any extra info about the issue you are trying to solve.