I posted about this earlier to the wireless networking forum, without responses, but I've since discovered that it's not actually a wireless issue.

Using my high-speed connection at home with a dual-boot laptop, Windows networking is fine, but Linux is unable to resolve host names. DHCP is able to determine all the usual information correctly, including the name servers in /etc/resolv.conf, but any attempt to connect to another host using the host name results in a lookup failure. Using host with the name server specified in the command line also fails. I can connect using IP addresses, and I can successfully ping the name servers. The same Linux system also works without problems when I connect it to the network at work.

Other details:
I'm running a hardened version of Fedora Core 1. This problem seems to have appeared while I was trying to set up wireless networking at home (the wireless networking and ethernet networking show the exact same behavior). Also, the name servers identified by DHCP (and successfully used by Windows) are in a different domain than my system, so maybe it's a firewall issue?

Any suggestions, please? Once I get this worked out I can finally stop booting to Windows altogether.

check the status of iptables and see what's happening with your firewall.

iptables -L OUTPUT

should list the current rules.

Thanks, iptables led to the solution. It appears that the firewall rules
added by the hardened version were causing the problem.