Xbox connects to wireless router (thomson TG585 v8) but not to internet?

[#1]

Hi all,
After my router (Thomson TG585 v8) from plus net finally being delivered, i set up my wireless network. The laptop, blackberry and sony C905 connects to the wireless network easily and the internet works fine.
For serveral hours i have tried to connect my xbox to the internet and then hopefully onto xbox live. .
All the network settings on the xbox are set to automatic, i scan for the network, find my router and enter the WEP2 password. An IP is allocated (this IP number however is the same number as the DSN server number?). The status changes to connected.
I test my xbox live connection and it connects to the router/network, then comes up with an error with regards to the DSN number and suggests entering the number mannually: So the things i have done so far with no sucessful outcome:
1. Restarted and reset the equipment (countless times). 2.  Ran ipconfig/all on my laptop to manually enter the DSN primary and secondary numbers. Only the primary shows up, entered the primary number in manually. 3. Entered the ip address, subnet mask to be same as computer. Ran xbox live test and it doenst connect to the router ig the ip details are entered as the same as the computer. 4. Removed the firewall on my router 5. Cannot connect via ethanet as router is down stairs (xbox directly above on first floor singal strength on xbox is 100%). 6. Entered the ip in address bar, IP and DSN which shows for router is different on laptop and if settings are on automatic on xbox network settings.
CAN ANYBODY HELP!?!?!?

[#2]

What he said.
I have exactly the same issue. Any help would be greatly appreciated. Thanks 

[#3]

Ive solved the problem...
I have changed my router from the one PlusNet supplied FOC. XBox live is now up an running.

[#4]

Which router did you buy? 
I have currently got my Xbox plugged in through my PC on my old modem like I did with my old ISP. Wireless would be a lot easier.

[#5]

Bump.
Still not solved my problem. I still get the DNS error message no matter what I do. Has anyone had this problem before and could they resolve it using the Thomson TG585 v8?

[#6]

Bump.
Afraid this is not a solution but someone else with the same issue. Anyone with any suggestions?

[#7]

WORKING! - But not sure how, or if replicable....
OK, tried a few things throughout the day to get this working and ended up blocking even my PC from the internet, so, I reset the router - do this by jamming a paperclip into the little reset hole next to the power button and holding it down until the power light turns red.
This evidently resets it to factory settings and you'll have to wait a few minutes for it to reset and then re-enter your setup details as per the first time you got your broadband up and running.
So, now back online, I was up for another go with the XBOX. Crucially for me my XBOX was now connecting to my network whereas before it was detecting it but not connecting.
Using the XBOX connection troubleshooter: http://support.xbox.com/en-us/pages/xbox-live/troubleshoot/connection-issues/connect-xbox-live.aspx
I followed the steps there but only had to manually enter the DNS settings before it connected.
Have now downloaded the system update and am setting up my account
Really hope this works for you guys! Sorry it's not more precise but this is how it's gone for me