I too have had a bad experience with a Maxtor drives in a Netgear SC101 NAS device.
http://kb.netgear.com/app/products/model/a_id/2537I too had security set to only allow specific users to access specific data on the network and one day it decided to allow everyone access to everything
Come to find out the NAS unit like an automatic update from Netgear through the software to administer it and it got a flash update that erased the security permissions and opened it wide open for everyone!!!
Reset the security permissions, and then 4 months later one of the hard drives failed in the pair of 320GB Maxtor Drives. Removed both hard drives to figure out which one failed since the device wont tell you, and had to plug them into a desktop computer as slave to test. ((( IT WAS THEN...That I found out that the drives were not using FAT32 or NTFS, but some inaccessible by Windows Partition type...so if my NAS died, I would LOSE ALL DATA without the ability to read the partitions. Popped the healthy drive back in and frantically backed up all data to my towers 500GB drive.)))
Then called Netgear support in Pakistan, and asked how I could access my data if the device failed. They said sorry each device had to initialize the drives in it and write a specific to that units serial number boot instruction and moving the hard drive to another SC101 I would lose my data when it would force to reformat the drive for that units chipset.
I hung up the phone with them, removed my hard drive, made sure there was a clear shot to the asphalt below and no danger to anyone or anything, and threw the empty NAS out the 3rd story window onto the parkinglot below. Then cleaned up the mess and shipped it back to Netgear with my complaint....Never heard a word from them. Biggest waste of money...
My suggestion is to make sure you mirror the data on your NAS with another systems hard drives extra drive capacity to avoid a total data loss. I would also remove one of your drives in your NAS mirror and see if its in a different partition table type that is inaccessible if the device failed as I found out with the Netgear SC101.
Generally I have always liked Netgears products, but this baby was a piece of junk.