Strange behavior with Double NAT

[Adam Skutt <LordHunter317@softhome.net>]

Hi--
I have a home network with a OpenBSD 3.1-STABLE machine routing my 
internet connection.  My personal machine is connected via 802.11b to 
the upstairs network.  I have attached a mac running OS X to my 
machine's ethernet card.  Normally I'd just setup a bridging network, 
but my 802.11b doesn't properly support promiscious mode and therefore 
cannot properly bridge.  

So, I simply enabled NAT on my 802.11b card, and the mac happilly talked 
to my network.  However, it wouldn't talk to most internet sites at 
all.  

As expected, it works fine when I take it upstairs and plug it in.  
Strangely, when I boot my machine into Linux and run iptables w/ NAT, 
it works fine as well.  I'm completely and totally stumped.  Any ideas?


-- 
--Greetings,
Adam Skutt