Problem with applet

I get the following message:

Certificate Not Verified

Code will be treated as unsigned

I've signed the applet using the following tutorial:

http://forum.java.sun.com/thread.jsp?forum=63&thread=174214

and verified as well using the jarsigner tool, so what can be wrong?

I'm using:

Java(TM) 2 SDK, Standard Edition

Version 1.4.2

[390 byte] By [ramonklowna] at [2007-10-3 2:29:34]