Netscape open port

[J C]

I seem to be having an issue with netscape navigator 7.1.  I don't use
Netscape hardly but it came with the ditro I'm using, Slackware 9.1.  I
run nmap on my network quite often.  What I have found is that everytime
Netscape is running port 5180 is open.  Nmap does not give any info
regarding the port and says it's unknown. I tried to establish a
connection with port 5180 and I recived a 404 error like some sort of
web service is running on it.

Does anyone know anything regarding Netscape and that particular port?

Thanks.