The following is the contents of my winsock.log file:

[02/03/05 21:27:24] event.cpp:(84): WSAENOTSOCK: One of the descriptor sets contains an entry that is not a socket.
[02/03/05 21:27:24] event.cpp:(84): WSAENOTSOCK: One of the descriptor sets contains an entry that is not a socket.

Looks like a typo somewhere.

This happens whenever you log off. Don't worry about it.