I understand that this is not the perfect environment for doing this but please stick with me and help if you can... The set up I want to achieve is to have my rails application running on a windows 2003 server, using a pack of mongrels with lighttpd acting as the load balancer and IIS in front of it all passing client requests to lighttpd. first of all i've followed these instructions: deploying to iis on windows And I've managed to get the application to run, BUT if the client clicks on a link button the app bombs out with a 500 server error. If I just run against one of the mongrel servers, the the app behaves ok, so I think its lightpd. Its almost as if the lighttpd gets confused with multiple GET requests (i.e. multiple clicks) and bombs out. Any help on why i'm getting 500 errors would be helpful, thanks.