help with promiscuous mode

I am running SimplyMepis, a debian-based distribution. My wireless card
is an Intel ipw2200.

When I use tcpdump or ethereal as root I am only seeing my own traffic
and running ifconfig shows that the network card is not in promiscuous
mode. If I then use ifconfig to set the card in promiscuous mode I
still only see my own traffic.

What kind of problem might I have with my configuration, or could it be
a problem with my ipw2200 driver, which is the latest version offered on
sourceforge.net?

Thanks.