share internet connection via internal airport with windows

I am not able to share my wired Internet connection to my Mac via the internal wifi card.

Here is my setup:

Intel iMac
SBC DSL modem plugged into my iMac via Ethernet

What I would like to do is to have the iMac share this wired, Ethernet connection via wifi.

What I did:

-Firewall turned off
-personal internet sharing turned on
-share internet connection tab has SBC DSL as the sharing source (there is no option for Ethernet) (this changed when I installed the SBC software on my mac to configure my modem)
-share internet connection tab has airport as what it will be shared through
-airport options (currently) has a network name, channel set to auto, and no security options (as in, no wep password)
-I push start sharing on the share internet connection tab

What happens:

-On my XP laptop (and on my wifi-enabled phone), it sees the network I created on my mac
-When I try to connect to it (both on my phone and XP), it "tries" but then gives up

Any suggestions?

I'm having the exact same problem ! any ideas? I have tried the above with both WEP on and off

I got part of the way to solving this problem. First, I turned WEP off. Second, I observed the IP address of Airport. Then, I assigned to my device a manual ip address in the same series as that of the Airport. I then used the same dns server as the Mac has and set the subnet mask as well. I got it to work.

However, when turning on WEP, it didn't work.

I got it to work! When you set the WEP key, make sure to set it as a "Shared" WEP key and not an "Open" WEP key.