Until RAIDiator 4.1.3 is released, there are two work-arounds if you are using FireFox 3 with the ReadyNAS administrative webpages...
- Install the Fix_Firefox3 addon/patch into FrontView via System>Update>Local (This only applies to pre-4.1.3 firmware users).
- Or update to recent RAIDiator firmware.
(for you geeks: FireFox 3 changed the way they send content-type values)
