Many of the 4th Gen Nano units have a new firmware that Apple has confirmed makes it difficult to work with several products on the market, including the Z410 dock.

Unfortunately, we don't have the authority to over-ride this new software, and it was placed there, according to the source I spoke with, due to copyright agreements with content holders.

They have suggested using an RCA to 3.5mm input and play the music through the headphone jack into the system itself.

I apoligize for this inconvenience, however, this affects 4th Gen Nano units and Classics.