[Samba] Who or what is IP client 0.0.0.0?

[taso]

Samba 3.0.21a

Getting a fair bit of activity logged from IP 0.0.0.0
What does it mean?

[2006/01/14 13:42:23, 0] lib/util_sock.c:get_peer_addr(1222)
   getpeername failed. Error was Transport endpoint is not connected
[2006/01/14 13:42:23, 0] lib/access.c:check_access(328)
[2006/01/14 13:42:23, 0] lib/util_sock.c:get_peer_addr(1222)
   getpeername failed. Error was Transport endpoint is not connected
   Denied connection from  (0.0.0.0)
[2006/01/14 13:42:23, 1] smbd/process.c:process_smb(1187)
[2006/01/14 13:42:23, 0] lib/util_sock.c:get_peer_addr(1222)
   getpeername failed. Error was Transport endpoint is not connected
   Connection denied from 0.0.0.0
[2006/01/14 13:42:23, 0] lib/util_sock.c:write_data(554)
   write_data: write failure in writing to client 0.0.0.0. Error Connection reset by peer
[2006/01/14 13:42:23, 0] lib/util_sock.c:send_smb(762)
   Error writing 5 bytes to client. -1. (Connection reset by peer)
[2006/01/14 13:54:23, 0] lib/util_sock.c:get_peer_addr(1222)