Hmm, I also have a IBM laptop, an X21 and RH9 runs on it like a champ, network works better than it has ever done on windows.
Looks like IBM is changing network cards and producers really frequently.
Some more troubleshooting for you that might show where the problem lies:
Check out knoppix, www.knoppix.com
It's a CD you can download and burn. Like this you can run linux off the CD.
Why I mention it? Because Knoppix is world famous for working on ANY HARDWARE. If it works on your, i.e. you get networking, you can see which driver it uses and maybe copy it.
You can order Knoppix per mail, if you cannot download it.
Good luck, hope it works for you. Knoppix has never failed me so far (funny fact: Just installed a brand new Benq TFT LCD monitor at a friends, windows XP did not recognize it, knoppix did)
If it works, would love to hear about it (also if it doesn't of course)