IPO trying to access nasystem in the TFTP server

[KaLLiSToi]

My IP 5000 is repeatedly trying to create a file (or directory) called 'nasystem' in the TFTP server, and is always failing.

From the TFTP server log, it seems the IPO is timing out w/o reason. The TFTP server is running well. I am pretty sure the problem is in the IPO, perhaps I have misconfigured anything.
___________________________________________________________

Connection received from 192.168.1.126 on port 10694 [24/11 10:30:00.254]

Write request for file <nasystem>. Mode octet [24/11 10:30:00.254]

Using local port 2703 [24/11 10:30:00.254]

File <nasystem> : error 10054 in system call recv An existing connection was forcibly closed by the remote host. [24/11 10:30:00.254]
___________________________________________________________

I am wondering what this 'nasystem' is and why the IPO fails in creating it.

Thanks in advance.