Cannot connect to nintendo wii

i have the siemens gigaset SE587 and it will not connect to the nintendo wii that i have. it will find the access point but will not connect. i have contacted nintendo and they have said that they are having a lot of problems with this type of router but not sure what is wrong. they seem to think that the router is stopping the wii from connecting to it somehow and need to change something on the router settings but dont know what!!! contacted tiscali and they were not helpful at all!! can someone please help!!! thanx!! :) I've also been struggling with the same problem for the past 2 weeks. Ringing Tiscali technical support was not fruitful and although Nintendo's website offers support for various makes of routers, unfortunatley it offers no solution to the Siemens Gigaset SE587. Any Techy Whizzkids out there able to offer their help? Thank you