RealVNC 4.1.3 free hangs in XP sp3

[jim]

The problem seems to be that client can't see the server as after reconnect
key strokes appear on the server.    Sometimes the hang won't repair with
restart but moving the Server mouse or running a program on the Server we
establishes the connection.

This is the error message in Event Viewer Application logs      HTTPServer:
error writing HTTP document:write: Connection aborted (10053)

Any ideas appreciated.