I have setup a hotspot using a web and radius server on a windows machine. When a user connects to my Wifi and opens a web browser they are redirected to my web page were they can log on and make connection to the internet. This all works like it suppose to using another windows os machine. However, I can not make connection to the web page using linux (SUSE10.0) using Firefox or Kontact.

Any ideas why it works on a windows machine and not a linux machine?

Is it the redirection that is not working or are the linux machines not able to establish any connection to the server? Did you try directly entering the server ip address/name into the address bar on the linux browser?
Btw i assume you meant Konqueror, for Kontact is an address book program?
Also if you know, how does the redirection work, is it based on dns (returning the address of the server for any query) or based on a firewall capturing http requests and sending them to the local web server?

You can read about the program here>> http://www.chillispot.org/features.html

I am using a WRT54G router that has the DD-WRT frimware which has the above software embedded.

When I type in the local address I still get "Unable to connect" and yes I meant Konqueror.

Would you be using the WPA mode for access?In that case perhaps the linux clients were not set up for wpa properly. In any case, it seems that it is a problem with the network rather than authentication - so the chilli software is probably not at fault. The only things i can think of are to check the networking functions of the linux clients - try pinging other computers, the router, etc from the linux machines. If you can ping the router from the linux machines, then you should be able to access the web page on the same ip, unless some weird things are going on like the linux firewall blocking http traffic(highly unlikely).