wireless, laptop, connect automatically

My laptop does not manage to connect anymore, while windows-xp just
works (no flames, please).
I acquired the laptop a month ago, and the first two weeks my connect
script worked most of the time.
I have no idea where to begin researching this. This is what I do in my
script:

ifconfig ath0 up
dhclient atho

There are two open networks where I sit, but one of them never responds
to DHCP requests.
I do not know what the network card actually does, why it succeeds when
it does, and why not, when it doesn't. I have tried to read the
wireless how-to but I have not found anything of relevance. What tools
are there that could help debug the problem?

I have wireshark, and it shows the dhcp discover requests, and some
traffic involving other hosts (promiscuous mode), but it is just like
my laptop's transmissions are not received in the other end.

Today I tried "iwconfig ath0" a couple of times while dhclient was
trying, and saw that it was using the essid of the network that never
responds. I then tried "iwconfig ath0 essid blah-blah", and after that
"iwconfig ath0" always report the essid I have set, but there is still
no repsonse. I also observe that each time I run "iwconfig ath0" the
frequency is different. It seems never to be what I get from "iwlist
ath0 scan". I guess it means the software is trying various
frequencies, but it does not quite make sense to me. Iwlist scan always
report the same frequencies.

I have debian, but this too is a new experiance for me. I used to
install redhat/fedora on my computers. Hence I do not know what is the
canonical way of setting up the network.

I have also tried to find out how Windows XP does it, and installed
wireshark in the windows partition too, but it seems it does not work
with my wifi card - Atheros AR5005G. The card gets listed in the
interfaces list, but there is never a single packet in the window. Yes,
tried non-promiscuous mode too.

Any ideas? Thanks

"(E-Mail Removed)" <(E-Mail Removed)> writes:

> My laptop does not manage to connect anymore, while windows-xp just
> works (no flames, please).

I (fedora core-6) used the system configuration utility (under gnome,
system -> administration -> network). Immediate and easy.

--
Maurizio Loreti ROT13:(E-Mail Removed) | (@_
Un. of Padova, Dept. of Physics, Padova, Italy | //\
http://www.pd.infn.it/~loreti/mlo.html | V_/_