Unknown Connection Problem (Lag)

[HomeWrecker]

I'm trying to play Halo 2 on X Box live and I'm getting alot of lag. About 5% of the time I can get through a game without a problem but Most of the time I can't play the lag is so bad, some games it starts ok but halfway through it shows up ( red bar and all).
Moved here about a year ago and go fiber optic line to the house and paid extra for 10mb down and 1mb up. I'm using a lynksys WRT54G and the xbox is now hardlined to it and has a static IP. Tried forwarding the normal ports, forwarding all of the ports, and the routers DMZ (open all feature).
I am running two desktops connected wirelessly to the router as well, when we play Halo they may be running AIM. I can't see them taking up alot of bandwith doing nothing but I did try turning one off and again not a fix or help at all. I did a speed test on DSLreports.com and the servers average around 600kps down and 250 kps up, I don't know if they should be around 10 mb down and 1mb up, like I pay for, but I'm not sure how those work. Is there anything I might be missing that could be causing me problems or Is my ISP giving me the shaft? They are a local ISP that was created by the borough because we have a college campus here and no big names were stepping up to bring us some high speed but they must have be going for about 5 years now and they spent big money on the project and act and price just like the big guys so I don't know what solutions might solve my problem but any ideas to pinpoint something would help.
Also, computer games seem to have no problem even running two at once.

[SPARTAN 0841992]

In my experience, Xboxs and routers do NOT like each other. I had both my computer and Xbox hooked up to a router, and lag issues occurred like you wouldn't believe. I was having trouble joining friend's games, playing matches, even sending messages. My advice: unplug your router and plug the cable for your Xbox directly into the modem. It is a relative inconvenience, having to power cycle each time you want to switch between the Xbox and the computer, but that's the absolute only thing that would get XBL running at full capacity.

[wulkar]

Xbox's and routers do not get along well, i have my PC and xbox on a lynksys router and it works fine, but let me tell you it took a good 5 months to get them to work right. if you havent already i would call 1800 4my xbox they helped me get it to work, if you have already done this then i dont know what to do to help you

[HomeWrecker]

Thanks guys. I did call that number thank you for it. They said the usual port forward try without the router stuff but I'm pretty good with all of that so already tried did it all. He said it might be the ISP they may not be "Xbox live compatible"? I have no idea what that means other than they were not checked by microsoft and labeled Xbox live compatible, so I don't really know the qualifications there but I'm gonna start bugging them now. Thanks for the replys.

[Kiddingo]

Up date your router's firmware.. I've got the same router and Have had as many as 2 360's and 2 PC's and 1 wireless Laptop all going at the same time with no problems.

[HaZarD SFD-XBA]

I use a D-Link 524. Its totally compatible with XboX Live http://www.dlink.com/products/?sec=1&pid=316

They also sell for $19-30. So they are a great deal for the price. Oh and they are wireless
too.