Sorry, I do not know anything about Macs.
The Storagebird LAN manual says:
Supported Operating System: Windows 98SE / ME / 2000 / XP, Mac OS X 10.2 and above
If "MAC OS X 10.2 and above" is the operating system of your Apple computer, it should work.
Which firmware do you have ? Version 1221 is the actual official version.
If this does not help, I would contact the FSC support via Internet (Sorry, I did not find the english site):
Maybe there is already a new beta firmware for the device that fixes the problem or, if not, they know about it and can fix the problem.