Hi all,
Yesterday I started to trying to use wstools but the following exception was thrown when I executed it:

log4j:WARN No appenders could be found for logger (org.jboss.ws.tools.WSTools).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.jboss.xb.binding.JBossXBRuntimeException: Failed to create a new SAX parser
 at org.jboss.xb.binding.UnmarshallerFactory$UnmarshallerFactoryImpl.newUnmarshaller(UnmarshallerFactory.java:100)
 at org.jboss.ws.tools.config.ToolsSchemaConfigReader.readConfig(ToolsSchemaConfigReader.java:131)
 at org.jboss.ws.tools.WSTools.readToolsConfiguration(WSTools.java:139)
 at org.jboss.ws.tools.WSTools.generate(WSTools.java:79)
 at org.jboss.ws.tools.WSTools.main(WSTools.java:61)
Caused by: org.jboss.xb.binding.JBossXBException: Failed to create a new SAX parser
 at org.jboss.xb.binding.parser.sax.SaxJBossXBParser.<init>(SaxJBossXBParser.java:69)
 at org.jboss.xb.binding.UnmarshallerImpl.<init>(UnmarshallerImpl.java:57)
 at org.jboss.xb.binding.UnmarshallerFactory$UnmarshallerFactoryImpl.newUnmarshaller(UnmarshallerFactory.java:96)
 ... 4 more
Caused by: java.lang.NullPointerException
 at sun.misc.URLClassPath$3.run(URLClassPath.java:316)
 at java.security.AccessController.doPrivileged(Native Method)
 at sun.misc.URLClassPath.getLoader(URLClassPath.java:313)
 at sun.misc.URLClassPath.getLoader(URLClassPath.java:290)
 at sun.misc.URLClassPath.findResource(URLClassPath.java:141)
 at java.net.URLClassLoader$2.run(URLClassLoader.java:362)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findResource(URLClassLoader.java:359)
 at java.lang.ClassLoader.getResource(ClassLoader.java:977)
 at java.lang.ClassLoader.getResourceAsStream(ClassLoader.java:1159)
 at org.apache.xerces.parsers.SecuritySupport$6.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at org.apache.xerces.parsers.SecuritySupport.getResourceAsStream(Unknown Source)
 at org.apache.xerces.parsers.ObjectFactory.findJarServiceProvider(Unknown Source)
 at org.apache.xerces.parsers.ObjectFactory.createObject(Unknown Source)
 at org.apache.xerces.parsers.ObjectFactory.createObject(Unknown Source)
 at org.apache.xerces.parsers.SAXParser.<init>(Unknown Source)
 at org.apache.xerces.parsers.SAXParser.<init>(Unknown Source)
 at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.<init>(Unknown Source)
 at org.apache.xerces.jaxp.SAXParserImpl.<init>(Unknown Source)
 at org.apache.xerces.jaxp.SAXParserFactoryImpl.newSAXParser(Unknown Source)
 at org.jboss.xb.binding.parser.sax.SaxJBossXBParser.<init>(SaxJBossXBParser.java:65)
 ... 6 more

I think it should be a problem related with my environment variables, but I have been taking a look at the forums and I am not able to fix it. I have checked my wstools.bat, and all libraries referenced in

http://wiki.jboss.org/wiki/Wiki.jsp?page=JBWSFAQClientJars

are correctly included.
Do you know if I have to include any other library as much as previous ones?
Do I have to modify any other environment variable?

Thank you very much in advance.