Ant task problem (not critical)

I'm having problems using ant to build my system inside jEdit + AntFarm.
For who don't know jEdit is a programmer's editor which offer
extensibility features through plugins, AntFarm is such a plugin which
feature the running of build process with Ant.

That said i'm having this exception when running my build within jEdit:
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:324)
	at org.enhydra.xml.xmlc.taskdef.Xmlc.execute(Xmlc.java:591)
	at org.enhydra.barracuda.taskdefs.Localize.execute(Localize.java:633)
	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:193)
	at org.apache.tools.ant.Task.perform(Task.java:341)
	at org.apache.tools.ant.Target.execute(Target.java:309)
	at org.apache.tools.ant.Target.performTasks(Target.java:336)
	at org.apache.tools.ant.Project.executeTarget(Project.java:1339)
	at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:397)
	at
org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:143)
	at org.apache.tools.ant.Task.perform(Task.java:341)
	at org.apache.tools.ant.Target.execute(Target.java:309)
	at org.apache.tools.ant.Target.performTasks(Target.java:336)
	at org.apache.tools.ant.Project.executeTarget(Project.java:1339)
	at antfarm.TargetRunner.runAntTarget(Unknown Source)
	at antfarm.TargetRunner.run(Unknown Source)
Caused by: java.lang.NoSuchMethodError:
org.w3c.tidy.Configuration.getTagTable()Lorg/w3c/tidy/TagTable;
	at
org.enhydra.xml.xmlc.html.parsers.tidy.TidyHTMLParser.setProprietaryTags(TidyHTMLParser.java:297)
	at
org.enhydra.xml.xmlc.html.parsers.tidy.TidyHTMLParser.parse(TidyHTMLParser.java:327)
	at org.enhydra.xml.xmlc.compiler.Parse.parse(Parse.java:232)
	at org.enhydra.xml.xmlc.compiler.Compiler.parsePage(Compiler.java:109)
	at org.enhydra.xml.xmlc.compiler.Compiler.compile(Compiler.java:224)
	at org.enhydra.xml.xmlc.commands.xmlc.XMLC.compile(XMLC.java:132)
	at
org.enhydra.xml.xmlc.commands.xmlc.XMLC.compileHandleErrors(XMLC.java:142)
	at org.enhydra.xml.xmlc.commands.xmlc.XMLC.main(XMLC.java:153)

The same build works perfectly outside jEdit (say from the console) so i
know the problem is not due to Ant and/or anttask but from some
classloading clashes inside jEdit.

I would only have a hint where to look (which class/package) to try to
find the point where the problem occurs, maybe some xml implementations
classes loaded inside jEdit or some of its plugins !?

Ant is 1.5.4 Java is 1.4.2_03 ...

Thanks
-- 
Thelmo