ok, that means the 301 redirect is not coming from mojoportal, it is coming from something else like an IIS module or Web.config settings, or maybe you have some default document other than Default.aspx and that other document could be redirecting.
Make sure that Default.aspx is the only default document configured in IIS
But one problem is even once you find out what is causing the 301 redirect and you stop it from happening, unfortunately web browsers also cache 301 redirects and it can be difficult to get them to clear that from the cache. You can remove the 301 but the browser will still redirect because of the browser cache.