Hi guys,
i've got the same problem. In System/Reporting the only graph which is shown is the "Diskspace"-graph all other graphs are emty.
I tried the tips above but nothing happened.
I'am running FreeNas 8 Release on a ASUS E35M1-I.
EDIT: I just updated to FreeNAS-8.0.1-BETA2-amd64 and all report graphs are no shown correctly