Strange Error (10038-CWSAENOTSOCK)

We are having a strange error occur on a client machine when using Delphi's
TClientSocket / TServerSocket on a single Win2000 machine. At first
communication is established between the two applcations and data is
transmitted without any problem. Connecting and disconnecting is always
successful. Then, at some indeterminate point, connection attempts begin to
fail with the following error:

Windows Define: CWSAENOTSOCK
Error Number: 10038
Short Microsoft Description: Socket operation on a non-socket.
Long Microsoft Description: An operation was attempted on somthing that is
not a socket. Either the socket handle parameter did not reference a valid
socket or, for select, a member of an fd_set was not valid.

Once this error occurs, there is no way to reconnect through the socket at
the given port that was active when the error was generated. Using a
different port does allow communications once again until the error occurs
at some seemingly random point again in the future.

This is only occuring on one of 20 or so computers - it is very frustrating.

Thanks in advance for any advice you might have.

Zachary Hartnett
Micro Software Solutions, Inc.