WCF and WebGet - Error when requesting files with extension

I have configured a simple method in my service that just sends back what you requested :

[WebGet(UriTemplate = "/{fileName}")]
[OperationContract]
string GetFile(string fileName);

And when I access this method via:

http://localhost:8460/WCFService1/Service.svc/file开发者_开发知识库Name

I get a respond containg the string "fileName".

But I want to be able to accept a request for a file with it's suffix like this : http://localhost:8460/WCFService1/Service.svc/fileName.jpg

In this case I get an error :

The resource cannot be found

(As if the request was not channeled to the GetFile() method).

It's a bug with the asp development server. When I host the service in webmatrix(IIS express) it works fine and requests made with extensions are ok.