<style> does not appear to use the classpath attribute for locating
xalan classes. 

my ant tag:
  <target name="trans-source" depends="init">
    <style basedir="${src.dir}/msg"
           in="${src.dir}/msg/request/LoginRequest.xml" 
           out="${src.dir}/com/converging/Beans/LoginRequestBean.java"
           style="${src.dir}/msg/msgBean.xsl"
           processor="xalan">
	<classpath>
	  <pathelement location="lib/xalan.jar" /> 
	  <pathelement location="lib/xerces.jar" />
	  <pathelement location="lib/xalanj1compat.jar" />
	  <pathelement location="src/msg" />
        </classpath>
    </style>

######my output:
trans-source:
Class org.apache.tools.ant.taskdefs.optional.XalanLiaison loaded from parent loa
der

BUILD FAILED

java.lang.NoClassDefFoundError: org/apache/xalan/xslt/XSLTProcessorFactory
        at org.apache.tools.ant.taskdefs.optional.XalanLiaison.<init>(XalanLiais
on.java:82)
        at java.lang.Class.newInstance0(Native Method)
        at java.lang.Class.newInstance(Class.java:237)
        at org.apache.tools.ant.taskdefs.XSLTProcess.resolveProcessor(XSLTProces
s.java:278)
        at org.apache.tools.ant.taskdefs.XSLTProcess.getLiaison(XSLTProcess.java
:394)
        at org.apache.tools.ant.taskdefs.XSLTProcess.execute(XSLTProcess.java:14
1)
        at org.apache.tools.ant.Task.perform(Task.java:217)
        at org.apache.tools.ant.Target.execute(Target.java:164)
        at org.apache.tools.ant.Target.performTasks(Target.java:182)
        at org.apache.tools.ant.Project.executeTarget(Project.java:601)
        at org.apache.tools.ant.Project.executeTargets(Project.java:560)
        at org.apache.tools.ant.Main.runBuild(Main.java:454)
        at org.apache.tools.ant.Main.start(Main.java:153)
        at org.apache.tools.ant.Main.main(Main.java:176)

Total time: 4 seconds
org/apache/xalan/xslt/XSLTProcessorFactory

#####But from the same directory:

javap -classpath lib\xalanj1compat.jar 
org.apache.xalan.xslt.XSLTProcessorFactory
Compiled from XSLTProcessorFactory.java
public class org.apache.xalan.xslt.XSLTProcessorFactory extends java.lang.Object
 {
    public org.apache.xalan.xslt.XSLTProcessorFactory();
    public static org.apache.xalan.xslt.XSLTProcessor getProcessor() throws org.
xml.sax.SAXException;
    public static org.apache.xalan.xslt.XSLTProcessor getProcessor(org.apache.xa
lan.xpath.xml.XMLParserLiaison);
    public static org.apache.xalan.xslt.XSLTProcessor getProcessor(org.apache.xa
lan.xpath.xml.XMLParserLiaison, org.apache.xpath.XPathFactory);
    public static org.apache.xalan.xslt.XSLTProcessor getProcessorUsingLiaisonNa
me(java.lang.String) throws org.xml.sax.SAXException;
}