wlan0 on a tosa built from org.openzaurus.oz354x stopped working....

I've had my wlan0 working, but something recently broke it.

I have a tosa and am building a 2.6 kernel from a recent snapshot of
the org.openzaurus.oz354x tree.

I've been using an /etc/network/interfaces file like the one described
here:

 http://openzaurus.org/wordpress/installation/sl-6000/

and it's been working fine.

Before I do anything else, I run modprobe ohci-hcd to power up the
wireless (and the green led goes on).

ifup now says:

   SIOCSIFFLAGS: No such device

when it's staring udhcpc (as reported by running ifup w/ -v).

ifconfig wlan0 shows the interface, but ifconfig wlan0 up reports the
same error as above.

I don't think that I've changed anything relevant [of course...].

I'm using a freshly built opie image and i've ipkg installed a bunch
of stuff to support a simple sdl app.

Help?

Thanks,!

g.