Stories like this are why I didn't buy a Drobo. Instead I got a ReadyNAS NVX and have been incredibly satisfied with it. It's been rock solid so far and hasn't given me any hassle at all.
(Incidentally, Netgear UK are doing a "free 2 x 500GB drives" promotion until the end of June: http://www.netgear.co.uk/freedrives_nvx.php)