Airport Extreme: Macbooks cannot connect to disk drive over wifi; LAN iMac can
On my MacBooks over Wifi, the HDD attached to the Airport does not mount in the same way as directly connected or even NAS drives. Rather than the drive, I get the Airport Extreme in the 'Shared' section of Finder. Selecting the Airport Extreme shows the drive as a folder, and opening that folder effectively 'mounts' it. Even then, the drive does not show as a drive within Shared or Devices, yet it is accessible.