Usually people want to go the other direction, but I want to take our relatively fast and stable house 802.11g signal and bridge it to ethernet. I have tried using an Airport Express (the b/g flavor) and my i7 MacBook pro, both to no avail. Word is that the b/g flavor of

This flavor of Airport Express maxes at firmware 6.3 which doesn't support this kind of bridging properly. However, I expected my MacBook pro to do the job with its "Internet Sharing" feature. Alas, although my wired PC does sort of see it, it doesn't work out. Strangely, using DHCP the PC receives the same IP address as my MBP uses on the network. Less strangely, but still surprisingly, the wired ethernet port on my mac registers as the IP address of the gateway when queried with IFCONFIG.

It sort of makes sense that the mac would "pretend" to be the gateway, but the whole thing just isn't working and seems configured wrong - but all the docs I see say basically "OS X Internet Sharing: click it and go".

What do I do? Do i really have to buy more hardware, even though I have plenty of would-be candidates for bridging?

Incidentally, the host router originating the 802.11g signal is a belkin 802.11g router, and is documented to support WDS.