is there a bug in XJC ? (underscore at the end of the package )

test.txt

/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/bin/xjc test.xsd 
parsing a schema...
compiling a schema...
host/ns_/ObjectFactory.java
host/ns_/Root.java
host/ns_/package-info.java


$ /usr/local/package/jdk1.7.0_07/bin/xjc test.xsd
parsing a schema...
compiling a schema...
host/ns/ObjectFactory.java
host/ns/Root.java
host/ns/package-info.java

test.xsd

<?xml version="1.0" encoding="UTF-8"?>
<!--

please run:

$ xjc test.xsd 

do you get:

parsing a schema...
compiling a schema...
host/ns/ObjectFactory.java
host/ns/Root.java
host/ns/package-info.java
 
or do you get (package with underscore)

parsing a schema...
compiling a schema...
host/ns_/ObjectFactory.java
host/ns_/Root.java
host/ns_/package-info.java



-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:myns="http://host/ns#"
    targetNamespace="http://host/ns#"
    elementFormDefault="qualified"
     attributeFormDefault="qualified"
    >
   
 <xs:complexType name="Root">
    <xs:sequence>
      <xs:element name="name" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>

<xs:element name="Root" type="myns:Root"/>


</xs:schema>