Retrieving documents with ":" in their ID requires different authentication when host name is IP address?

When retrieving documents with ":" in their names (http://127.0.0.1:45665/test/coffe%3Atea), basic HTTP authentication is required. When accessing the same document on localhost (http://localhost:45665/test/coffe%3Atea) no credentials are prompted for, as expected.

Steps to reproduce:
1. Log in to futon.
2. Create the database test.
3. Open test and create a document with the ID "test" and save it.
4. Access /test/test and verify that it is accessible.
5. Create a new document with the id "coffe_tea".
6. Access /test/coffe%3Atea and verify that authentication is required.
7. Change the hostname from 127.0.01 to localhost and verify that the document does not require authentication.

I have tested this on CouchDB 1.0.1 on Natty