Why can’t an Windows ME PC ping a Windows XP PC?

I have a Windows XP PC with a local printer that is shared and a Windows ME machine on the same network, both with dynamic IP addresses. I was able to print from the ME PC to the shared printer on the XP PC. Changed the IP address on the XP PC, now cannot print from the ME PC.

Also, the XP PC can ping the ME PC but the ME PC cannot ping the XP PC. The ME pc can ping other XP PCs with static IP addresses.

Can anyone offer help?