Error on Extension FtpWebRequest

Error on Extension FtpWebRequest

  
I've installed Extension FtpWebRequest in a 4.1 express edition server. When I try to request a dir command or something else in FtpRequestSample app, an exception message from extension occurs:

Unable to cast object of type 'System.Net.FtpWebRequest' to type 'FtpWebRequest'.

The extension was made to 3.1+ versions that use .NET 1.4, it has anything to do with .NET (v 2.0) plataform on 4.1 plataform server?


Thanks