I think that may account for some of your issues! Most especially your problems connecting you game servers. I also find it strange that you can't connect both systems to the internet at once. To be honest, that sounds a lot more like dial-up than ADSL!
Kooky Brits.
Actually, I have this same problem, but I think I know why.
For reference, I'm in America, using Comcast as an ISP. 2.5megs/down 1.5megs/up. Pretty sweet deal with the Cable TV and three free premium channel-sets included for like 60 bucks... Anyway...
When we switched over the the Internet/TV Package and the whole Digital-only thing went live, I had to get a new modem. Comcast told me I needed theirs. I ignored them. I wasted 60 bucks on a modem. I had them install theirs. (For reference, I'm living with my mom while going to school, and she's not exactly tech-savvy, so I handle all this stuff.) The tech was shocked that all my wiring was already in place. (Yeah, I learned how to do all that stuff when I was eight buddy, get over your trade-school degree.) He handed me the modem, confident I could figure it out, and didn't even charge me for the visit. Nice guy.
Now, we'd previously been using a LinkSys something or other Wireless Router/Gateway/Modem. We were, once upon a time, able to connect four computers to the same internet connection. There was a time where we actually had four computers in this house. But since we switched, we haven't been able to have more than one connected. We can't just Daisy-Chain the new Modem through the old LinkSys Router, and the new one just plain didn't work. I sent it back to LinkSys and got a full refund for a defective product. Explained a lot.
So, I went out and bought another one. Took out the Comcast Modem, plugged in my new one... Still wouldn't work... Though, stuff actually lit up this time, but I never got the DS, US, or Online lights to turn on... Can't fathom why. Plugged in the Comcast Modem again.
So here's what I'm thinkin'... Something about the nature of my connection requires that I have their modem plugged in. Comcast has also told me that I'm good to go on Home Networking, so all I need to do is plug in a Hub or Router and watch the magic work... We've already established that my old Modem/Router/Gateway won't do the job, and I assume this is because of hardware conflicts with the nature of the Modem/Router/Gateway. My mom and I have been looking absolutely EVERYWHERE for a plain old Router Hub... And we cannot find one. BestBuy doesn't have them, our Mall doesn't have them, no one freaking has them, and without actually knowing what to look for, we can't find them online without shipping them from Canada or the UK... So... My Question is...
Where the hell can I find just a plain old Router Hub for sale, and are there any recommendations on what I should look into? Internet is a life-style in this house, and sharing my hard-earned computer with my Mom is frustrating... And so is sharing our hard-earned internet via one computer... HEEEEEEEELP!