java.lang.NullPointerException at .XMLJUnitResultFormatter.formatOutput(XMLJUnitResultFormatter.java:253)

[somath . nao]

I'm trying to get the jUnit task to show the results in a xml format, 
however, when I add  "<formatter type="xml" />" in the Ant build script I 
get java.lang.NullPointerException at 
.XMLJUnitResultFormatter.formatOutput(XMLJUnitResultFormatter.java:253) 

Error Output: 
    [junit] java.lang.NullPointerException 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.XMLJUnitResultFormatter.formatOutput(
XMLJUnitResultFormatter.java:253) 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.XMLJUnitResultFormatter.setSystemOutput(
XMLJUnitResultFormatter.java:92) 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.sendOutAndErr(
JUnitTestRunner.java:435) 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(
JUnitTestRunner.java:319) 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.launch(
JUnitTestRunner.java:672) 
    [junit] at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.main(
JUnitTestRunner.java:567) 
    [junit] Exception in thread "main" 

Here's what I have in the ant build file: 

                <junit printsummary="yes" fork="yes" haltonfailure="yes" 
showoutput="no"> 
                        <classpath> 
                                <path refid="compile.classpath" /> 
                        </classpath> 
                         <formatter type="xml" /> 
                        <test name="com.funb.doit.net.TestHelloWorld" 
outfile="result" > 
                                <formatter type="xml" /> 
                        </test> 
                </junit>