Junit tests failing when triggering Maven build using JDK 1.6

My project build succeeds when I use Java 1.5. But fail on 1.6 for some unusual reasons. I see that only my JUnit tests fail. Some genuine assertions which used to pass on 1.5, fail throwing exceptions on 1.6. I tried changing the maven-compiler-plugin to 1.6, tried a newer version of JUnit to run the test cases. But no help. Any reason why? Thanks!

Edit: Adding one such exception. Pretty much all look similar to this:

Tests run: 3, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.047 sec <<< FAILURE!
testThis(TestConn)  Time elapsed: 0.016 sec  <<< FAILURE!
java.lang.AssertionError: expected:<com.sun.net.ssl.internal.ssl.SSLSocketFactoryImpl@e61a35> but was:<com.sun.net.ssl.internal.ssl.SSLSocketFactoryImpl@c2b2f6>
    at org.junit.Assert.fail(Assert.java:74)
    at org.junit.Assert.failNotEquals(Assert.java:448)
    at org.junit.Assert.assertEquals(Assert.java:102)
    at org.junit.Assert.assertEquals(Assert.java:117)
    at com.test.conn.ex.TestConn.testThis(TestConn.java:80)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:59)
    at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)
    at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)
    at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)
    at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)
    at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)
    at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)
开发者_开发技巧    at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)
    at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)
    at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
    at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62)
    at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140)
    at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:127)
    at org.apache.maven.surefire.Surefire.run(Surefire.java:177)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:345)
    at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1009)