Recently there was a question in the newsgroups where a user had the problem that their roles were not working correctly. Users with a particular security role could see the windows they were not supposed to see. The problem seemed complicated, but the solution was simple.
It turned out, with the help of MVP Leslie Vail, that the problem was just that the security checkbox was not checked on in the company setup window!
Mark covered this in his weekly review - “You MUST check the Security checkbox in Tools-Setup-Company-Company if you want security to be active.” http://msdynamicsgp.blogspot.com/2009/08/weekly-review-that-little-security.html