Failure on jython when forcing opt-compilation

When running jython from the DaCapo 9.12 benchmark suite (the 2006-10-MR2 jython runs fine) such that all methods are optimized at least at level O0, the benchmark fails with the following exception:

./dist/production_ia32-linux/rvm -X:aos:enable_recompilation=false -X:aos:initial_compiler=opt -X:irc:O0 -jar dacapo-9.12.jar jython
error importing site
Traceback (most recent call last):
File "/home/sewe/Desktop/hg/jikesrvm/scratch/jython/Lib/site.py", line 0, in <module>
java.lang.NullPointerException
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyCode.call(PyCode.java:18)
at org.python.core.imp.createFromCode(imp.java:326)
at org.python.core.imp.createFromSource(imp.java:289)
at org.python.core.imp.loadFromSource(imp.java:511)
at org.python.core.imp.find_module(imp.java:411)
at org.python.core.imp.import_next(imp.java:635)
at org.python.core.imp.import_first(imp.java:656)
at org.python.core.imp.load(imp.java:564)
at org.python.util.jython.run(jython.java:165)
at org.python.util.jython.main(jython.java:117)
at org.jikesrvm.classloader.ReflectionBase$$Reflect40042.invokeInternal(Unknown Source:0)
at org.jikesrvm.runtime.ReflectionBase.invoke(ReflectionBase.java:180)
at org.jikesrvm.runtime.Reflection.invoke(Reflection.java:74)
at java.lang.reflect.VMCommonLibrarySupport.invokeStatic(VMCommonLibrarySupport.java:203)
at java.lang.reflect.VMCommonLibrarySupport.invoke(VMCommonLibrarySupport.java:172)
at java.lang.reflect.VMMethod.invoke(VMMethod.java:88)
at java.lang.reflect.Method.invoke(Method.java:330)
at org.dacapo.harness.Jython.<init>(Jython.java:36)
at org.jikesrvm.classloader.ReflectionBase$$Reflect39897.invokeInternal(Unknown Source:0)
at org.jikesrvm.runtime.ReflectionBase.invoke(ReflectionBase.java:180)
at org.jikesrvm.runtime.Reflection.invoke(Reflection.java:74)
at java.lang.reflect.VMCommonLibrarySupport.construct(VMCommonLibrarySupport.java:436)
at java.lang.reflect.VMConstructor.construct(VMConstructor.java:87)
at java.lang.reflect.Constructor.newInstance(Constructor.java:317)
at org.dacapo.harness.TestHarness.runBenchmark(TestHarness.java:211)
at org.dacapo.harness.TestHarness.main(TestHarness.java:171)
at Harness.main(Harness.java:17)

java.lang.NullPointerException: java.lang.NullPointerException

When using the baseline compiler instead, the benchmark passes.