Sub-folder web.config namespaces remove broken in 4.0?

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I am porting a web application to 4.0. It has a root web.config that adds a namespace:

  <namespaces>
    <add namespace="Insignia.Catalog2"/>
    ...
  </namespaces>

There is a sub-folder to this app with its own web.config:

  <namespaces>
  开发者_开发问答  <remove namespace="Insignia.Catalog2"/>
    <add namespace="Insignia.Catalog"/>
  </namespaces>

.Catalog and .Catalog2 have overlapping class names. This worked great in ASP.NET 2.0 thru 3.5 but seems broken in 4.0 - that is, I now get compiler errors about the colliding class names.

Well I figured it out. While the 'remove' tag WAS removing .Catalog2, another DLL had changed to include a reference to that namespace. Using a control from that other DLL brought .Catalog2 along with it! Fixing the reference solved the problem.