I configure the ps3 in the DMZ only to find I cant connect to AJ last night for a league game....1st time I couldnt connect to someone since NCAA 07 I think.
Anyway, I verify my settings for DMZ. I open the ports just in case, I assign the ps3 highest priority and all that shit.
still nothing.
I go direct from modem to ps3, no luck.
so then I know its not the router, its the modem.
I go back to my old house and modem and realize and some points I "Bridged" the modem...effectively turning off all Security features for it (which are a waste anyway), allowing traffic to pass freeley through it.
BOOM, reset router and it worked.
By "worked" I mean I forgot to mention that I was checking the status on my ps3 menu and I was getting the dreaded NAT 3 status.....
After bridging the modem, I now have NAT 2 and can hopefully connect to AJ tonight.
IF anyone is having problems I'd say contact your service provider and ask them for a link or file that shows how to "bridge" your modem....on mine it was very easy..it was a button that said "bridge"

others seems u have a little more leg work
you can also google it.
AJ, your time is almost up