IIS 7.0 - File Caching Issue

Hello.

I have a .NET website which connects to a web.config file.
I have no issue connecting to the site until I add a Host Name.
Once the Host Name is entered, the site redirects itself to an non-existent URL.
(Non existent in the sense that this file no longer exists.)

I'm also unable to change the URL - it keeps defaulting back to the same non-existent URL.
The only thing I can think of is that the Host Name is cached to this non-existent URL.

Can anyone assist me in letting me know what I can do to fix this issue?
Thanks,
Stephane