Actually XP Pro is phenomenal at locating shared resources and displaying them *however*, on the downside XP too often takes control of these network connections, implementing firewalls and bridges, which the user had no desire to utilize.
So first take a look at the Network connections. Is the Local Area Connection being firewalled by XP? If so disable this. Is there a network bridge listed on your network connections screen. Are any of your network connections listed, as being in the bridge? If you're troubleshooting a dialup (including VPN) connection, activate the connection, and observe whether this connection moves to the network bridge.
If you verify all the settings to be correct. My next question regarding the 2k shared printer is to ask if the XP pro computers have compatible drivers installed?
Just some thoughts.... I'm actually really appreciating XP Pro in a domain environment NT4, & 2k AD domains, even though I really didn't want to welcome it.