Scanner class i JDK 1.5 beta virker ikke i jBuilder X

Har netop installeret JDK 1.5 beta for at få adgang til klassen Scanner.
I J Builder X kan jeg finde Scanner via API'en (java.util.Scanner), men den kommer aligevel med denne fejl ved kompilering:

"Untitled1.java": cannot access java.util.Scanner,bad class file: C:\Programmer\Java\jdk1.5.0_05\jre\lib\rt.jar\java\util\Scanner.class,class file has wrong version 49.0, should be 48.0,Please remove or make sure it appears in the correct subdirectory of the classpath. at line 3, column 18

koden ser således ud:
------------------------------
package shcool;

import java.util.Scanner;

public class Q3_1
{
    public static void main (String[] args)
    {
        int intX1, intY1, intX2, intY2;
        double douDistance;

        Scanner objScan = Scanner (System.in);

        System.out.print ("Enter the coordinate of x1: ");
        intX1 = objScan.nextInt();
        System.out.print ("Enter the coordinate of y1: ");
        intY1 = objScan.nextInt();

        System.out.print ("Enter the coordinate of x2: ");
        intX2 = objScan.nextInt();
        System.out.print ("Enter the coordinate of y2: ");
        intY2 = objScan.nextInt();


        douDistance = Math.sqrt(Math.pow((intX2 - intX1), 2) + Math.pow((intY2 - intY1), 2));

        System.out.println (douDistance);
    }
}

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(tabuleringen blev smadret da jeg pastede det ind her, sry.)


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