Lennart_T,
I am shocked that you of all people would say such a thing (see the second and third paragraphs) about the UG.
Since I'm sure you're just as tired as I am of dealing with the lack of UG updating, I suggest you write (which I've done) to Rod Harrison—the Chief Technology Officer of Drobo who probably now has some influence at Retrospect "Inc". If you want to impress him with a Swedish-stamped "snail-mail":
Drobo
Attn.: Mr. Rod Harrison, CTO
1289 Anvilwood Ave.
Sunnyvale, CA 94089
USA
However, if you are willing to enroll in LinkedIn—which I am not because of delete-finger tiredness—you should be able to get an e-mail address for Harrison there.
P.S.: What Lennart_T and I said about the User's Guide not being updated is still valid; Nigel Smith's post below goes beyond what the UG says.