Using iTunes to play music on two Airport Expresses simultaneously

Hi everyone,
I'm trying to set up a system where iTunes 7.0 on my Windows 2000 PC can play simultaneously to two Airport Expresses.
I've set up the first AE (call it AE1) by connecting it to my LAN with an Ethernet cable; it appears in the Base Station Chooser and I can find it and set it up. I set it up to 'Create a wireless network' and check both boxes in the iTunes tab, and give it an iTunes speaker name. At this point, everything's happy: I can see AE1 in iTunes, and play music to the speakers, and my Nintendo Wii can even get to the internet using AE1. I've left AE1 plugged in to the network.
Now the problem: I bought another Airport Express, call it AE2, and I want the new one to hook up to the existing network and let me play iTunes through the new one, as well. I connected AE2 to my LAN with ethernet and it showed up in the Base Station Chooser; I set it up to 'Join an Existing Wireless Network' and gave it the exact same Network Name: "Mike Home Network". I checked both checkboxes in the iTunes tab and gave the speakers a name. I then unhooked the ethernet, plugged in the speakers to AE2, and unplugged and replugged AE2 to restart it. The light flashes green, goes to yellow for a while, then goes solid green. (So I assume it found a network to hook up to.) iTunes shows the Multiple Speakers button, and I can pick AE1, but no sign of AE2.
I restart iTunes, but it still can't find AE2. Some support suggests using the wizard, but I'm on 2000 so it's not supported.
So my questions:
* Can I verify somehow that AE2 hooked up to the network that AE1 created? Ping it or telnet to it or something? (I can ping AE1 just fine.)
* Is 'Join an Existing Network' the right way to do this?
(I also tried WDS with no success, but I may have done it wrong.)
* AE1 is distributing IP addresses; AE2 is not. Is this correct?
Access Control is turned off on both AE's.
I have Wireless Security set to 'Off' on both.
(I'll re-enable it once I get these two going.)
They're about 20 feet apart.
Wireless channel is 'Automatic' on both. (Also tried it with both on channel 8)
Firmware on both AE's is 6.3
Itunes is version 7
Any suggestions? Anything at all, I'm absolutely stumped and this seems like it should be really straightforward....
  Windows 2000  

Figured it out! thanks everyone for the help.
In the end, I fixed it by turning off 'Distribute IP Addresses' on AE1.
The problem was, if you want iTunes to find the wireless Airport Express, iTunes must be able to see the wireless AE's IP address. When AE1 was distributing IP addresses, it was performing NAT, which meant that iTunes on my PC could not distinguish between AE1 and AE2 behind it.
This is not clear in any of the documentation; I can't be the first person to be confused by this.