Make sure that that the console is programmed on a even port (Eg. 0, 2, 4...). The problem could also be with the console itself, they are getting pretty old.
The choice for new consoles are 4059 or 4049.
The 4059 consoles work on a Windows XP PC, which means that it can get a virus or any other PC related problems may occur.
The 4049 is just the Alcatel Multimedia Keyboard and a Normal Screen. Much less problems in the long run and cheaper.