I have a wireless network in my office that is working fine, with one exception; we can print over the wired network, but printing over wireless is a problem. We are using a wireless router with security enabled. Wireless clients are using Windows XP Professional, and both the network printer and the wireless router are connected to the same Ethernet switch.
You do not describe how clients are communicating with your network printer, but my guess is that you are using a Microsoft workgroup or domain with network file and printer sharing. If so, clients must have required services and ports enabled on both Ethernet and wireless adapters.
In XP, go to the Network Connections control panel on a wireless client. Choose the wireless adapter and right-click Properties. Select the General tab and make sure that both the "Client for Microsoft Networks" and "File and Printer Sharing for Microsoft Network" boxes are checked. Then select the Advanced tab and click the Windows Firewall Settings button. If the firewall is enabled, use the Exceptions tab to make sure that "File and Printer Sharing" is checked. If this does not do the trick, very carefully compare Ethernet connection settings on one of your wired PCs that has no trouble printing to wireless connection settings to spot differences. If you use a third-party personal firewall program, check that firewall's interface or zone settings to verify that NetBIOS is permitted over wireless.
This was first published in November 2006