Does the MAC detect the presence of a USB drive? If it does, then I would suspect it is a file sytem issue. If not, then It's probably a hardware issue. Try to use it on a PC, and see if PC can detect it.
There are no problem whit other USB on the MAC and the n1050 works well on the pc, and to copy files from the camera works well to. I have also copy files from a card reader (hama) but I can't have my Transcend multi card reader to function eather. The transcend works well on both MAC and PC.
I have just bought the Nano and am really annoyed to find that it doesn't work with my Mac. I am running OSX 10.5.4 on a Core 2 Duo MacBook. I know the unit is functioning correctly as have tested with my PC and having researched on the net have found several people having known problems with OSX / Intel Macs.
I can't believe that Thecus are not taking any action to resolve this and it is still being sold as Mac compatible. Would be really great if someone finds a solution to this as I've just wasted £25 (+£40 for a new hard drive) on a unit that won't work as advertised. Not happy.