Connecting to a non airport router

hey
i have a siemens gigaset router in my house
and when i try to connect to it it shows full signal and everything looks good
but it has no connection whatsoever, like its not running slow or anything

i was just wondering if its some sort of setting i need to change or if i should to get an airport express or something??

thanks

It might not be compatible with your airport card as airport cards are 802.11g
To be safe I'd just pick up a "Linksys Wireless 54g" router at Wal-Mart for $30. They're compatible and cheaper.

thanks
will that be as good of a signal strength at the airport?

Never had an airport express. I have an airport extreme card in my macbook and I can surf the internet 500 feet away from my house. However if you do not wish to get an airport extreme card, the airport card will work great and has a great range as well.