Hosting Error - Routers

For some reason, which I don't even dare to comprehend, all of a sudden I'm not able to host games when using my wireless router. I have hosted many times on it with no difficulties, but all of a sudden I'm not able to. I myself set up as a DMZ host and when I go to try to host a game, Civ freezes on me and the only way out is ctrl+alt+del. However, and this is wierd, when I plug in my old wired router, everything works fine and dandy. Any suggestions?

Wireless Router - Linksys WRT54G

I have upgraded the firmware, I'm running windows xp sp2.

I'd really like to be able to use my wireless router and still host a game.

If you've upgraded to XP SP2, then perhaps its something to do with that - perhaps its XP that's suddenly not allowing it to run (increased netowrk security etc)?

I did recently upgrade to SP2, but I was able to host fine for over a week after, and it's not just my computer. My two laptops can't host either unless plugged into my wired router. Also, and this is wierd as hell too, if I reset factory defaults in my wireless router, I can host once, and I mean once. After I exit out of the host screen or finish a game the first time, it goes back to freezing when I try to host.

It sounds like something is over-writing the factory settings, possibly at start-up of windows? Is there a software interface driver or similar that starts? Does it have some sort of settings that over-write the router factory settings? Some sort of preferences setting? Maybe they are user-specific, and different accounts over-write the main or something?

Have you tried tech-support for your router?