I have the same problem, but some is diffrent:
I use it to copy my backups to an external ftp host, an one file's size is about 1306 Mbyte.
When I try to copy it, it copies round 70%, and aborting then with the error message:
Der Socket ist nicht verbunden (107)
The socket is not connected (107)

I guess my translation of the error message is correct.
Please send a solution to sf@ddr-ware.de