hi, if you do not need any data that is on those drives that are currenly inside your drobo, then you could try the reset process. (dashboard has a reset feature button)
if that doesnt work, then in some cases it might be better to reset while empty, and to upgrade to the latest versions of firmware (and most proably dashboard too in your case as you are starting from scratch again)
and to reboot the drobo a couple of times (and computer just to make sure that all is still working fine after the firmware and dashboard upgrades)
and then when the unit is empty and on, to put those disks in 1 at a time, (seeing which ones the drobo accepts and assimilates into the new pack), before putting the next one in, until all are there (ideally accepted).
if you still have problems please post back though, and with some more info about the drives you have and drobo versions in case anyone spots any incompatibility etc.