may I ask you to answer following questions?
1. Could you please check if default.aspx page is enabled on your IIS?
2. What version of IIS/.NET are you using on your server?http://technet.microsoft.com/en-us/library/cc754807%28WS.10%29.aspx
3. Does the default page exist in your project folder?
4. Have you configured extensionless or are you using some custom extensions?
5. Would it be possible to grant us with an access on your development server, where we can see the redirection issue? I tried to reproduce it on my environment, but have no luck.
6. Is your server configured as a full trust or medium trust? Is virtual path provider running on your server?
Please send an email with login information to firstname.lastname@example.org (if it is possible) with reference to this thread.