Thanks for the replies.
I was messing with the host name and domain because it wasn't working with them set to defaults.
I tried inserting the default gateway address, madwifimoody, as 192.168.1.1 (my ADSL routers IP address). I did get an internet connection of sorts, but it was amazingly slow. Now I can't seem to get anything. When I try loading a web page in the browser it says Error loading
http://www.domainname.co.uk/ Unknown host (or something similar).
The card is shown as using the RT2500 chipset in YaST. Do I need to mess with the driver? Hope not as I wouldn't know where to start.
Signal strength isn't brilliant at this machine but I don't think that's the problem because it works consistently in Windows. Have disabled firewall for testing.
I've been doing some research and have tried using iwconfig. The funny thing is, no matter what settings I put into the YaST control panel they don't seem to be reflected in the iwconfig output... I don't understand. The interface my wireless card is listed as being on in iwconfig is ra0.