This is more of a comment than a question. In the IT industry, the concept of a guest account is commonly a violation of any corporate security policy. The ability to view main folder structure of any NAS system with a Guest account seems completely unacceptable to me.
Please, please, please update the next version of firmware to disable this Guest feature. It is not suited to a NAS product and any IT department that buys this product MUST have the option to disable the Guest account. I bought the Linkstation Pro Duo as an inexpensive reliable solution. After realizing that the Guest account could not be disabled, I turned it off in my IT lab. I plan on purchasing about 20 of these for my company and will not do so until that Guest feature is disabled. Thanks very much.
