Hi , I am having issues with an xbox 360 connecting to the internet via a TG585 v8 (new ) router wireless after having been kicked out of lounge to grarge!

situation is PC works fine via lan cable , also laptop works fine via wireless , also xbox works fine via lan cable , BUT when connected via wireless the xbox gets an IP address and connects to the router fine but goes no further and wont connect to internet ( security settings have been verified etc). Have tried assigning the game service in the router but to no avail?

to complicate matters further have tried another TG585 v7 which connects the xbox wireless with no problems at all and no special settings , Telecom kindly supplied another v8 to try which is exaclty the same ,  any ideas of settings that need to be changed in the new one ?? (am newish to this )