After upgrading to 3.0 I have two problems...
First I found that users listed on the "Permissions -> Read access" settings can't access to any report page except to "Right Now". They can't access to any other report (i.e. Overview, Visitors...).
Admin users can access to all reports, but (non admin) users listed in "Permissions -> Read access" can't access.
So then I tried to save options again, remove options from database and setting all again... and then I found that saving options is not working properly. Permissions options are not saved in the slimstat options array in database.