Search engines believe that http://www.hugon.ws and http://www.hugon.ws/default.aspx are two separate pages. They believe that these pages have the same content and this affects SEO.
The right thing to do here, is HTTP 301 redirect the default.aspx page to http://www.hugon.ws by applying the following rule:
<rule name="Canonical Page" patternSyntax="Wildcard" stopProcessing="true">
<match url="default.aspx" />
<action type="Redirect" url="/" redirectType="Permanent" />
</rule>Below is a screen shot of the Edit Rule UI in IIS:
