soapui eclipse plugin - java.lang.NoSuchMethodError

Hi,
i installed the soapui eclipse plugin (v 3.6.1) and i have an issue when i try to add a WSDL file...
I use JRE 1.5

The error is as follows :

ERROR:java.lang.NoSuchMethodError: javax.swing.JDialog.getModalityType()Ljava/awt/Dialog$ModalityType;
java.lang.NoSuchMethodError: javax.swing.JDialog.getModalityType()Ljava/awt/Dialog$ModalityType;
at com.eviware.x.impl.swing.JFormDialog.show(JFormDialog.java:183)
at com.eviware.x.impl.swt.Swt_AwtXFormDialogBuilder$DialogBridge.show(Swt_AwtXFormDialogBuilder.java:150)
at com.eviware.soapui.impl.wsdl.actions.project.AddWsdlAction.perform(AddWsdlAction.java:94)
at com.eviware.soapui.impl.wsdl.actions.project.AddWsdlAction.perform(AddWsdlAction.java:55)
at com.eviware.soapui.support.action.swing.SwingActionDelegate.actionPerformed(SwingActionDelegate.java:89)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
at javax.swing.AbstractButton.doClick(AbstractButton.java:302)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1051)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1092)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:231)
at java.awt.Component.processMouseEvent(Component.java:5517)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3135)
at java.awt.Component.processEvent(Component.java:5282)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3984)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3819)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Component.dispatchEvent(Component.java:3819)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

Could you help me...or not ?

Thanks