I don't usually post LBI tips but my latest client had an issue with User/Group Rights on a report that bothered me. We set up the Elements, Structures and Rights correctly but when we tried to access the report we got an error saying no rights existed for the user.
What we found (with help from Lawson support) was that the Start Date for the Right had to pre-date the oldest historical instance of the report. We Published a report on the 15th and created the Right (with a start date of the 15th). We had to back date the Right's start date to the 14th for the user to be able to view the report.
By the way, if you Burst a report with a Schedule, all users of that report have to have User/Group Rights set up correctly or the Bursting process won't work. No historical instances will be created and no Email notifications will be sent out.