原来，罪魁祸首是IIS的 URL重写模块。我已经定义了重定向调用规则的 Default.aspx的（这是设置为启动网站页）到站点的根目录，这样我可以有一个典型的家庭地址。但是，显然VS曾与这个问题，得到了困惑。当我使用赫利的ISAPI_Rewrite因此它甚至没有想到我检查这个问题并没有发生。

Turns out that the culprit was the IIS Url Rewrite module. I had defined a rule that redirected calls to Default.aspx (which was set as the start page of the web site) to the root of the site so that I could have a canonical home URL. However, apparently VS had a problem with this and got confused. This problem did not happen when I was using Helicon ISAPI_Rewrite so it didn't even occur to me to check.

我结束了从头开始创建一个全新的网站，并在一点一点地移植项目/文件到我的解决方案和重建我的web.config，直到我发现了这一点！ 好吧，至少现在我已经使用.NET 4.0（到目前为止，我希望不会碰到任何墙壁）略有更清洁的网站 - ！但什么是痛

I ended up creating a whole new web site from scratch and porting projects/files over little by little into my solution and rebuilding my web.config until I found this out! Well, at least now I have a slightly cleaner site using .NET 4.0 (so far, hopefully I won't run into any walls)--but what a pain!