[news.eclipse.newcomer] Error evaluating in scrapbook

[Stefano Tamburini <stefanotamburini@xxxxxxxxx>]

I can't evaluate expressions in the scrapbook.
I've got a "Hello World" program like this:
------------------------
package org.eclipsebook.mypackage;

public class MyClass {
        public static void main(String[] args) {
                System.out.println("Hello world.");
        }
}
------------------------

Then I try to evaluate this with Ctrl-U in the Scrapbook.jpage:
---------------------------
String[] args= {};
org.eclipsebook.mypackage.MyClass.main(args);
---------------------------

The system crunches away for a while, then pops out this message:
"Unable to launch scrapbook VM
 Reason:
    Cannot connect to VM
 Details:
    com.sun.jdi.connect.TransportTimeoutException"

The OS is Debian 4.0r0, and software (included eclipse and java) has been
installed with "aptitude". Eclipse version is 3.2.1.
Any help would be appreciated. I don't know where to start from.
Thanks
Stefano