Question about Wireless (again)

[Anthony Papillion]

Hello Everyone,

I really hate to bug the list with this again but the solution I used
last time for this problem didn't work this time and I've been
Googleing for over 3 hours and can't find an answer. I do hope someone
look past my newbiness and take time to help me out.

I have an Acer Aspire 5100 notebook and I had Ubuntu 7.10 working
absolutely fine on it earlier tonight. A friend of mine thought it
would be funny to reinstall Windows on the system so he backed up my
files and when I got home I had a shiny new XP system waiting on me.
Of course, I immediately pulled out my CD and reinstalled Ubuntu. Now,
the wireless won't work.

Last time, all I had to do as type 'iwconfig' to find my wireless card
was configured as ath0 (it is again now). Then I simply typed 'sudo
ifconfig ath0' to bring the interface up and connect to my wireless
network. My network has no protection as I want to run an open AP for
everyone.

Tonight, the laptop simply would not connect to the router. Other PC's
were connected so I know the router is accepting connections. I am
using the 192.168.1.X addressing scheme but for some reason this
laptop is being assigned a public address and different subnet mask
than the rest of my network. When I manually configured the interface
using 'sudo ifconfig ath0 192.168.1.1 netmask 255.255.255.0 up' it
looked like the if came up but there was no entry in my routers dhcp
clients table and I still didn't have internet access.

I am sitting her absolutely pulling my hair out. I KNOW there is
something simple I'm missing. Can anyone lend me a hand to figure out
what?

Thanks!
Anthony