non ordered structure in non ordered structure

The following mapping works fine for me:

<mapping name="..." class="de....">
<structure set-method="set..." get-method="get..." usage="optional" ordered="false">
<value name="..." field="..." usage="optional"/>
<structure name="..." usage="optional">
<value name="..." field="..." usage="optional" type="java.util.Date"/>
<value name="..." field="..." usage="optional" type="java.util.Date"/>
</structure>
</structure>
</mapping>

When i change the second structure to ordered="false" (and that is what i need) i get this stacktrace:

Error running binding compiler

• • • Error during code generation - please enter a bug report for this error in Jira if the problem is not listed as fixed on the online status page ***

java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.ArrayList.get(ArrayList.java(Compiled Code))
at org.jibx.binding.classes.MethodBuilder.appendLoadLocal(MethodBuilder.java:1094)
at org.jibx.binding.def.NestedStructure.genFlagTest(NestedStructure.java:327)
at org.jibx.binding.def.NestedStructure.genContentUnmarshal(NestedStructure.java:244)
at org.jibx.binding.def.ObjectBinding.genUnmarshalContentCall(ObjectBinding.java:795)
at org.jibx.binding.def.ObjectBinding.genContentUnmarshal(ObjectBinding.java:940)
at org.jibx.binding.def.ComponentProperty.genContentUnmarshal(ComponentProperty.java:256)
at org.jibx.binding.def.NestedStructure.genContentUnmarshal(NestedStructure.java:193)
at org.jibx.binding.def.ObjectBinding.genUnmarshalContentCall(ObjectBinding.java:795)
at org.jibx.binding.def.ObjectBinding.genContentUnmarshal(ObjectBinding.java:940)
at org.jibx.binding.def.ElementWrapper.genContentUnmarshal(ElementWrapper.java:315)
at org.jibx.binding.def.MappingDefinition.generateCode(MappingDefinition.java:582)
at org.jibx.binding.def.DefinitionContext.generateCode(DefinitionContext.java:603)
at org.jibx.binding.def.BindingDefinition.generateCode(BindingDefinition.java:661)
at org.jibx.binding.Compile.compile(Compile.java:305)
at org.jibx.binding.Compile.main(Compile.java:385)
at de.fraunhofer.iao.arpos.utils.JiBX.compileKostenvoranschlag(JiBX.java:44)
at de.fraunhofer.iao.arpos.utils.JiBX.main(JiBX.java:29)