The full error that I am getting is:

error for wireless request "Set Mode (8B06)
SET failed on device ath0; Invalid argument

The connection fails.

My OS is FC4 on a laptop, LC2210D. I have a Belkin Wireless G Router. The only change I made recently to the network configuration was to bind to my MAC address on the laptop and edit the allowed MAC addresses on the router. Even after the changes I was able to connect.

What is my next step to resolve this issue?
Thanks

What mode are you trying to set?

There are only two reasons you will get that error. One is you are trying to set a mode the hardware doesn't support (like Monitor or Master) or two, you are trying to configure a device that doesn't have any wireless extensions (like an Ethernet card).

I am definitely attempting to use a wireless device unless when I set the MAC for the wireless I accidently set it for the ethernet device. How can I be certain what the MAC is for the wireless?

I had the same issue in FC 5. I ran 'depmod' and it fixed it.

How do I use "depmod" to resolve my problem?

How do I use "depmod" to solve this problem?

I ran: depmod -e

I continue to get the same error.

you still haven't said what you are trying to set. can we have the command and error as you see it?

It is very likely that the person asking does not or cannot know which exact command is causing the error message, because he is simply running
system-config-network and/or calling ifup wlan0 or something like that.

an one find out the exact offending command by tracing through ifup wlan0?

i have exact the same trouble, let me explain myself.

i have an acer aspire 4320 with a wireless card atheros ar5007eg, i have two partitions on my laptop one for xp and the other one for the fedora 9 (i have to tell i kind of ... nahh i actually a newbie on linux) i install fedora 9 and then i couldnt find my wireless card, so reading i see that madwifi exist and i download and install the madwifi drivers, it looks working i found wlan0 and everything looks pretty normal, but .... i can not connect to my wireless lan.

So i go back on my steps and checking this new whole and unknowing world and i found network giving me this message, i couldnt activate the device because 8b06, so i can not connect on any wireless lan.

So i hope that you can help me,

greetings

Im going to write at least my solution here, i feel pretty stupid after figure out what was the problem or what was going on on my last post.

I can see that the problem it wasnt on my card or the madwifi drivers, or something else, the problem it was at the configuration of the wireless.

Please i recomend that double check the configuration of your wireless, my problem was security mode "open" or "shared".

and it get done.