I have error 1437

Hi,

I try to connect my 4th generation Ipod nano, with my computer and when I plug in the Itunes popes up, and says: your ipod seems to be corrupted. If i try to reconnect, it does the same, and I couldn't restore it because after erasing the Ipod, Itunes says: Your Ipod can not be erased, unknown problem (1437)

What can I do?

Thanks for everything,

Zoltán Kárpáti