Can the firmware on these be downgraded after it has been upgraded? My NAS which is on 1.66 has a message to say that an upgrade to 1.71 is available but before I upgrade I want to make sure that I can downgrade if I want to. Reason for wanting to do this is I have opened up SSH on the NAS to allow me Telnet/SSH access and if upgrading to 1.71 blocks this then I'd want to downgrade back to 1.66.