I never use "1" on a TCPIP client module, I always use a connection manager to connect to the device when needed and close the connection after. This can be as short as a few milliseconds to send a command and acknlowledge the answer or as long as the system or page is in used, but never 1.
I never had any problems this way.
At least disconnect from the device when it's not in use is a good idea.
