Is IE using a proxy server? I would guess that IE is not resolving the domain name properly, you might try adding 127.0.0.1 dnndev.me to your hosts file in c:\windows\system32\drivers\etc\ in case IE isn't getting the public DNS records for that domain name.
edit: You might also try running Fiddler to see if the requests are going external, instead of internal when run through IE.
Also, double check that it isn't just a "Default" document issue, put default.aspx on the end of the URL