Problems with the Using Statement and WCF client

I've been wrapping all the code that invoke WCF calls within an using statement in a thought that the object will be disposed properly. When I'm googling for an exception "Http service located at .. is too busy" I found this link http://msdn.microsoft.com/en-us/library/aa355056.aspx that says should not use using statement in typed proxies. Is that really true? I think I got a big code change (sigh). Is this problem comes only in typed proxies?

Sample code:

private ServiceClient proxy;

using(proxy = new ServiceClient("ConfigName", "http://serviceaddress//service.svc")){
    string result = proxy.Method();
}