Hi, it's been a while since you posted, so perhaps you've fixed this? Anyway, my troubled experience was that after upgrading the Mac OS X earlier this spring, the DMS (none of the partitions) were recocnized or showed up in Finder or Disk Utility. I tried quite a few fixes, and eventually found that this works consistently for me:
Insert the DMS into the cradle
Shut down the Mac and leave it off for a minute
Power up again, still with the cradle connected and DMS inserted
This mounts the DMS and I can use PhatMac as before.
BJ