I was trying to get my Intel 3945ABG wireless card on my Sony Vaio (VGN-FE550G; Centrino Duo T2300) working, and replaced the default ieee80211 subsystem with the latest from sourceforge - version 1.1.14. Except, apparently, with my kernel version (2.6.17-1.2145_FC5 - Fedora Core 5, latest kernel) I wasn't supposed to replace it.
Now I'm stuck as to how to get my default ieee80211 subsystem back. Do I reinstall the kernel? (If so, how? If it helps in any way, I still have my old kernel on my system, version 2.6.15-xxxx - don't remember, I can find it if it's crucial.)