openjpa enhancer fails on one-to-many, but only if its after one-to-one? - jpa

Question

I get the following exception when I have my open JPA entity mapping set up with a one-to-many mapping listed after a one-to-one mapping. When I switch the order, I don't get the exception.
I'm assuming that there is an XSD rule being applied, but what is the purpose of that rule?
Failed to execute goal
org.apache.openjpa:openjpa-maven-plugin:2.2.2:enhance (enhancer) on
project: Execution enhancer of goal
org.apache.openjpa:openjpa-maven-plugin:2.2.2:enhance failed:
org.xml.sax.SAXException: Invalid content was found starting with
element 'one-to-many'. One of
'{"http://java.sun.com/xml/ns/persistence/orm":one-to-one,
"http://java.sun.com/xml/ns/persistence/orm":many-to-many,
"http://java.sun.com/xml/ns/persistence/orm":element-collection,
"http://java.sun.com/xml/ns/persistence/orm":embedded,
"http://java.sun.com/xml/ns/persistence/orm":transient}' is expected.
<!-- FAILED -->
<entity class="com.test.comm">
<table schema="dbo" name="tbl_comm_data"/>
<attributes>
<id name="commId">
<column name="comm_id"/>
</id>
<basic name="commName">
<column name="comm_name"/>
</basic>
<one-to-one name="CommType" target-entity="com.test.TblCommType" mapped-by="TblComm" fetch="LAZY">
<cascade>
<cascade-merge/>
</cascade>
</one-to-one>
<one-to-many name="CommDtls" target-entity="com.test.TblCommDtl" mapped-by="tblCommFreq">
<cascade>
<cascade-merge/>
</cascade>
</one-to-many>
</attributes>
</entity>
<!-- WORKED -->
<entity class="com.test.comm">
<table schema="dbo" name="tbl_comm_data"/>
<attributes>
<id name="commId">
<column name="comm_id"/>
</id>
<basic name="commName">
<column name="comm_name"/>
</basic>
<one-to-many name="CommDtls" target-entity="com.test.TblCommDtl" mapped-by="tblCommFreq">
<cascade>
<cascade-merge/>
</cascade>
</one-to-many>
<one-to-one name="CommType" target-entity="com.test.TblCommType" mapped-by="TblComm" fetch="LAZY">
<cascade>
<cascade-merge/>
</cascade>
</one-to-one>
</attributes>
</entity>