intermittent JCK test failures under stressed-out execution

HS 2.0rc1G / JDK 1.2.2 fails when executed under WinNT in -Xcomp mode against
the following JCK-stress tests:
    nsk/stress/jck12a/jck12a006
    nsk/stress/jck122/jck122012

These tests belong to the 'testbase_nsk', which is located at:
    /net/sqesvr/vsn/testbase/testbase_nsk
The mentioned tests are located in the sub-directory:
    ${TESTBASE_NSK}/src

These tests are based on JCK 1.2a and on JCK 1.2.2 cerrespondingly, and
they try to execute large bunches of JCK tests simultaneously as concurrent
threads. Both these tests usually fail on the following two JCK tests:
    vm/classfmt/ins/instr_049/instr_04901m1/instr_04901m1.html
    vm/concepts/execution/execution062/execution06202/execution06202.html
having the following 'main' classes:
    javasoft.sqe.tests.vm.classfmt.ins.instr_049.instr_04901m1.instr_04901m1
    javasoft.sqe.tests.vm.concepts.execution062.execution06202.execution06202
And intermittently, other JCK test also fail, which are involved into the
JCK-stress tests 'jck12a006' and 'jck122012'.

I've found, that the JCK test 'execution06202' seems invalid for me; and I'm
just going to file a bugreport against it. However, the test 'instr_04901m1'
looks valid. And I did not found in JCK exclude-lists those JCK tests involved
into the stress-testing, wich fail intermittently.

So, I believe that there is some problem in HS revealed by the mentioned
JCK-stress tests.

To execute them, you need to have the following stuff in the CLASSPATH:
    /usr/local/java/sqe-tools2.0/javatest.jar
    /usr/local/java/jck1.2/JCK-runtime-vm-12a/classes (needed only for tests: jck12a005-008)
    /usr/local/java/jck1.2.2/JCK-runtime-vm-122/classes (needed only for tests: jck122007-013)
Also, it is necessary to compile the stress-wrapper:
    ${TESTBASE_NSK}/src/nsk/stress/share/StressTest.java
and append its binary to the CLASSPATH.

Note, that some JCK tests need '-Xfuture' or '-verify' option to run correctly;
so you need to set '-verify' option to execute the JCK-stress tests, e.g:
    java -Xcomp -verify jck12a006 2>log