Getting NPE when group is included - selenium

Question

I hope you can help me on the following issue...
I am running a test that includes one class, in this class I have two methods. One belong to group G1 and the other one to G2.
If I use exclude group, the test is executed, if I use include group, test is skipped getting NPE.
I am using Eclipse 3.6 , Testng 6.8.
Example:
Test class:
public class{
#Test (groups = {"G1"})
public void Test1(){
...test code...
}
#Test (groups = {"G2"})
public void Test2(){
...test code...
}
}
Works:
<test name="Test_Name" preserve-order="true" >
<groups>
<run>
<exclude name="G1"/>
</run>
</groups>
<classes>
<class name="Test.class" />
</classes>
</test>
Test2 is executed.
Fails:
<test name="Test_Name" preserve-order="true" >
<groups>
<run>
<include name="G1" />
</run>
</groups>
<classes>
<class name="Test.class1" />
</classes>
</test>
Log:
java.lang.NullPointerException
at xxxxxxxxxxxxxxxxxxxxxxx.Test1(UsersTest.java:32) First line of the method
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod
(MethodInvocationHelper.java:84)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods
(TestMethodWorker.java:127)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
at org.testng.SuiteRunner.run(SuiteRunner.java:240)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
at org.testng.TestNG.run(TestNG.java:1057)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)
Thanks!