I entered options for two ethernet cards (3c59x's, if it matters) after Kudzu found them, but in linuxconf only one of them is visible under the `basic host configuration', and it's not set as `Enabled'. Grumble.
What does the /etc/sysconfig/network-scripts/ifcfg-eth<whaterver> look like? Does it work otherwise?
After noticing the oddity, I manually set it up with linuxconf. After seeing notting's comment, I removed ifcfg-eth*. I re-ran kudzu, and it created those two files (ifcfg-eth0 and ifcfg-eth1). linuxconf showed them the second time, although they're not set as Enabled.
If this is the bug I think it is, it's fixed in the upcoming errata release of linuxconf.