It seems that the bug has been fixed in trunk-version 2625. It happened in trunk-version 2621.
My kernel is 2.4.20.  I can try to use oops if still need to catch the screen.
No this type of kernel panic in trunk-2625 now.

> Date: Mon, 30 Jul 2007 06:54:34 +0200
> Subject: Re: [Madwifi-devel] trunk version may cause kernel panic when only one open-auth wep
> From: mrenzmann@madwifi.org
> To: ccxxyy@msn.com
> CC: madwifi-devel@lists.sourceforge.net
> Hi.
> > Does anyone meet same scene as me?
> Probably, but it's hard to tell as you left out the most interesting part
> (the kernel oops message). You might want to check the existing tickets on
> madwifi.org to see whether someone else already reported about a similar
> problem.
> > 1, create ath0 on dev wifi0
> ...
> You should provide the exact chain of commands you use rather than
> explaining what they do.
> > And Kernel panic after 2-3 seconds. Display"..0x..Kernel
> > panic....Alee....". I think you can get that on your screen if do so.
> Probably, probably not. For that reason you should also provide us with a
> full dump of the resulting decoded oops message.
> http://madwifi.org/wiki/DevDocs/KernelOops might help here.
> Further information about your environment (such as the kernel version you
> use) would be interesting, too.
> Bye, Mike

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