SSL Certificate for SoapUI 4.6.4 not working :((((

Hallo everyone! 

I'm trying to send a client certificate in a REST Request but I keep receiving the response "401 Unathorized". I configured the certificate in the project preferences, just like it's explained  here http://geekswithblogs.net/gvdmaaden/archive/2011/02/24/how-to-configure-soapui-with-client-certificate-authentication.aspx 

Is it a general problem for this version? Does it work SSL Client Certificate with any other version? Which one would it be?

Thanks!