SWTException: Invalid thread access

[hispeedsurfer]

Hello,
I have try to use Eclipse SWT with a Seam-Application.
But sometimes, not every time, I receive an exception caused by:

SWTException: Invalid thread access

Here the class use SWT:

package org.jboss.util;

import org.eclipse.swt.SWT;
import org.eclipse.swt.ole.win32.OleAutomation;
import org.eclipse.swt.ole.win32.OleClientSite;
import org.eclipse.swt.ole.win32.OleFrame;
import org.eclipse.swt.ole.win32.Variant;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class OLEaccess {

 private static Display display = new Display();
 public OLEaccess(){
 }
 public static int OUTLOOK_MAIL_ITEM = 0;



 private Shell shell = new Shell(display);

 private OleFrame frm = new OleFrame(shell, SWT.NONE);

 private OleClientSite site = new OleClientSite(frm, SWT.NONE, "Outlook.Application");

 private OleAutomation auto = new OleAutomation(site);

 private int[] GetNamespaceDispId = auto
 .getIDsOfNames(new String[] { "GetNamespace" });

 private Variant Namespace = auto.invoke(GetNamespaceDispId[0],
 new Variant[] { new Variant("MAPI") });

 private OleAutomation NamespaceAutomation = Namespace.getAutomation();

 private OleAutomation mailItemAutomation;


 public String send(String to, String subject, String bodyTxt) {
 int[] LogonDispId = NamespaceAutomation
 .getIDsOfNames(new String[] { "Logon" });

 int[] LogoffDispId = NamespaceAutomation
 .getIDsOfNames(new String[] { "Logoff" });

 NamespaceAutomation.invoke(LogonDispId[0], new Variant[] {
 new Variant("YOUR MAIL ACCOUNT"), new Variant("YOUR PASSWORD"),
 new Variant(true), new Variant(true) });

 int[] CreateItemDispId = auto
 .getIDsOfNames(new String[] { "CreateItem" });

 Variant mailItem = auto.invoke(CreateItemDispId[0],
 new Variant[] { new Variant(OUTLOOK_MAIL_ITEM) });

 mailItemAutomation = mailItem.getAutomation();

 int[] ToPropertyDispId = mailItemAutomation
 .getIDsOfNames(new String[] { "To" });

 mailItemAutomation.setProperty(ToPropertyDispId[0], new Variant(
 "YOUR " +to));

 int[] SubjectPropertyDispId = mailItemAutomation
 .getIDsOfNames(new String[] { "Subject" });

 mailItemAutomation
 .setProperty(SubjectPropertyDispId[0], new Variant(
 subject +" "
 + System.currentTimeMillis()));

 int[] BodyPropertyDispId = mailItemAutomation
 .getIDsOfNames(new String[] { "Body" });

 mailItemAutomation.setProperty(BodyPropertyDispId[0], new Variant(
 bodyTxt));

 int[] SendDispId = mailItemAutomation
 .getIDsOfNames(new String[] { "Send" });

 mailItemAutomation.invoke(SendDispId[0]);

 NamespaceAutomation.invoke(LogoffDispId[0]);


 return "send";
 }

 public boolean dispose(){
 boolean rs = true;
 shell.dispose();

 auto.dispose();

 NamespaceAutomation.dispose();

 mailItemAutomation.dispose();

 site.deactivateInPlaceClient();
 site.dispose();

 frm.dispose();
 return rs;
 }
}

and the EJB

package org.jboss.business;

import java.io.Serializable;

import javax.ejb.Remove;
import javax.ejb.Stateful;
import javax.ejb.Stateless;

import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.annotations.Destroy;
import org.jboss.seam.ScopeType;
import org.jboss.util.OLEaccess;

@Stateful
@Name("outlookAccess")
@Scope(ScopeType.SESSION)
public class OutlookAccessAction implements OutlookAccess, Serializable {

 private OLEaccess ole = new OLEaccess();

 public String doAction()
 {
 ole.send("[e-mail]", "Invoke SWT fom J2EE Webapp", "was langw wärt wird endlich gut");
 //ole.dispose();
 System.out.println("Action Called");
 return "success";
 }

 @Destroy @Remove
 public void destroy() {
 ole.dispose();
 }
}

All swt dependencies are added to project.

Any idea?

Thanks
Andreas