It occurred to me that Rick Kelly wrote in gmane.os.netbsd.general:

> Have you thought about the possibility that there may be interference with
> your wireless network from some other wireless network? ( or cordless phones,
> and other consumer electronic junk)

Probably - I live in a city. However, this doesn't seem to affect the same
laptop, using the same network card, under Windows - and I really don't
think a bad connection should warrant a kernel panic. There's one other
reasonably strong network[1] and a few faint ones - but they're on different
frequencies.

Just when i thought removing '-march-pentium4' solved everything, it went
kaboom again. Right after I ran 'rtsol atu0'. Coincidence? Maybe, maybe
not.

[1] An open one, no less. Very annoying; my network card keeps associating
    with it if I'm too slow with feeding it the ssid and nwkey of my own
    AP.