I don't know if this helps, but this is exactly what I did to solve my issues with Arionet 350 card and Red Hat 9.
I downloaded the drivers from
www.cisco.com, but instead of downloading the newest 5.xxx.20 drivers, I downloaded the 4.xx.30 (or something similar). After that, I used WinXp to update the firmware. After the update, I used ACU to check to make sure that the card had the proper drivers and it worked under WinXp.
Afterwords, I decided to reboot my laptop and did a fresh install of Red Hat 9. I removed all linux partitions, and did a personal/home install. (I decided that I wanted to make sure the card worked and I don't need the extra stuff for now). I had noticed that the card will not recognize under the installation process, so don't be alarmed if there aren't two beeps during installation. After installation was complete, the computer rebooted.
After the reboot, I selected to boot up Red Hat 9. I looked at the messages that was flashing through the screen and watched for the message on loading up eth0 (my RJ45 network). Afterwords it started to load up the PCMCIA device. This is where the 2 beeps should be. If it is a fresh install and the firmware is correct there shouldn't be any problems.
NOTE: I tried to use the driver CD that Cisco provided with the card for linux. Instead of recognizing the card, it made the system not recognize any wireless device. I probably installed the drivers wrong, but the lesson is that if it is a fresh install everything should work out perfectly.
SIDE Note: Instead of using Red Hat 9, cause I heard people are complaining about it, I tried out Suse 8.2 eval. So far everything works out fine with the Arionet 350 card and Suse 8.2. So when that distribution of linux comes out, you might was to try that out.
Hope that helps...
Gigan