How to REALLY restart networking?

[Klistvud <quotations@aliceadsl.fr>]

Howdie, fellow Debianites!

I'm running Lenny with Gnome on two boxes, both connected wirelessly 
via network-manager to 
my home router. Problem: about once to thrice a day, one or both of the 
boxes randomly disconnect (they are using the proprietary Broadcom 
wl.ko and ndiswrapper, respectively) and I can't seem to make them 
reconnect. The nm-applet doesn't show the available networks anymore. 
Which are the services I should restart to make networking restart from 
scratch? 
What I've tried so far and *doesn't work*:

-- running /etc/init.d/networking restart
-- running /etc/init.d/networking-dispatcher restart
-- killing the Gnome nm-applet and starting another instance thereof 
from a Gnome-Terminal
-- running all of the above in every picturesque combination I could 
think of
-- running ifup, ifdown
-- logging out and logging in again
-- turning wireless off and on with the hardware button on the box 
which has one
-- all to no avail

-- rebooting - oddly enough, this helps. After a reboot, network-
manager reconnects flawlessly, and everything runs fine for another day 
or so.

How does one REALLY restart wireless in Debian without rebooting?

TIA

-- 
Certifiable Loonix User #481801