CRM 4: Insufficient Permissions

I faced a weird issue where some of the users with same role privilege in CRM Titan can not log on to CRM web. After doing some research and study the CRM trace log text file, the workaround is to grant at least an user level on Write User Setting in the specific role.
(at least a value 1 in PrivilegeDepthMask column in RolePrivileges Table)



You can find on the security setting page>roles>Business Management Tab.