I have an onboard Atheros wireless G card in this Toshiba Satellite M55-S139 laptop. I'm running the latest dapper with all updates installed.
I've got the 2.6.15-23-686 kernel.
I'm using NetworkManager, though I get the same behavior using the normal Network Monitor applet.
What happens is what looks like a kernel panic. It occurs the exact same moment a wifi network is connected to, and never before.
If I'm in X, the whole thing just locks up.
If I set NetworkManager to connect to a wifi network and then quickly page to tty1, I see a kernel panic message. Most of it is scrolled off screen before I can make out anything useful.
If I start connecting to a wifi network and quickly switch to tty2, I see the message: "[4295144.337000] BUG: soft lockup detected on CPU#0!"
I should probably note the sporadic nature of this bug. When I first installed dapper at flight 7, everything worked fine. About a week later, after several updates, this started happening. I rebooted a couple times, switched to an older kernel, and it stopped. After that, wifi worked again with any kernel till about beta 2, then the bug came back. I connected to an wired connection and installed the flight 7 update, and it worked again. Three days later, it broke. I connected to a wired connection again and installed the latest updates, but it's still not working.
I haven't really seen a patten between when the bug comes and goes, but some updates seem to fix it for a while.
Just rebooted after getting the error message, let the computer sit for like half an hour, then connected without a problem. Don't know why.