PPT talk button error: Failed to connect to COM4

[jpq]

When I start up the VizPPT software I get these messages:
# of adapters in this system : 2
Interface #1 type : 24
Interface #2 type : 6
MAC Address of interface #2: 004ca3a6b29


then when I press the talk button i get this:
Failed to connect to COM4

this used to start up the vrpn server but it stopped working and I have no idea why. Nothing has changed about the system settings as far as i know.