WiFi port 'Firewalled' and IP Protocol Errors

Whenever I activate the Firewall on the computer's ethernet
port that connects to the MN-520 Base Station (before and
after installing WinXP SP2), my NetMedic software (version
1.2.2 - copyright 1997, VitalSigns Software; long
discontinued), that monitors the Net Connections, shows a
Yellow Warning with a message "IP Protocol experiecenced an
IP errors performance problem".

When this firewall (not the base station one) is turned
off, NetMedic shows 'all gren-lignt'. No problems.

I know, I'm being 'prissy' on this, for everything is
working fine and no connections problems whatsoever.

But... why is NetMedic reporting IP errors? (my guess: old
software, not prepared for today's security precautions?)

I keep this ethernet port firewalled (as well as using the
Base Station's internal firewall). But this Yellow Warning
troubles me for I don't usually ignore WarnLights.