Web Service and IIS 6

Hi all
I’ve got an asp.net2 application that is consuming a simple web service. This works fine on the development machine. When i deploy it to production server which is running IIS6, it does not work it comes up with the error shown below. I thought it was an issue with the rights on the temp folder but i have done this and still it does not work. SOMEBODY PLEASE HELP THIS IS DRIVING ME NUTS.