If you try to add a new runtime within ESB Project Wizard, you will get the following exception:

eclipse.buildId=I20080617-2000
java.version=1.5.0_14
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Framework arguments: -product org.eclipse.sdk.ide
Command-line arguments: -product org.eclipse.sdk.ide -data E:\workspace-3.4M7-JBoss\plugins/../runtime-New_configuration -dev file:E:/workspace-3.4M7-JBoss/plugins/.metadata/.plugins/org.eclipse.pde.core/Test/dev.properties -debug E:\workspace-3.4M7-JBoss\plugins\.metadata\.plugins\org.eclipse.pde.core\Test/.options -os win32 -ws win32 -arch x86 -clean -console -consoleLog

Error
Mon Oct 06 12:30:29 CEST 2008
Invalid thread access

org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(SWT.java:3777)
at org.eclipse.swt.SWT.error(SWT.java:3695)
at org.eclipse.swt.SWT.error(SWT.java:3666)
at org.eclipse.swt.widgets.Widget.error(Widget.java:463)
at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:355)
at org.eclipse.swt.widgets.Combo.removeAll(Combo.java:1205)
at org.jboss.tools.esb.project.ui.wizards.pages.ESBFacetInstallationPage.initializeRuntimesCombo(ESBFacetInstallationPage.java:293)
at org.jboss.tools.esb.project.ui.wizards.pages.ESBFacetInstallationPage$1.handleEvent(ESBFacetInstallationPage.java:92)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.notifyListeners(FacetedProjectWorkingCopy.java:1640)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.resumeEventNotification(FacetedProjectWorkingCopy.java:1685)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.setSelectedPreset(FacetedProjectWorkingCopy.java:1054)
at org.eclipse.wst.web.ui.internal.wizards.NewProjectDataModelFacetWizard.setRuntimeAndDefaultFacets(NewProjectDataModelFacetWizard.java:261)
at org.eclipse.wst.web.ui.internal.wizards.NewProjectDataModelFacetWizard$2.propertyChanged(NewProjectDataModelFacetWizard.java:212)
at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelImpl.notifyListeners(DataModelImpl.java:346)
at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelImpl.notifyPropertyChange(DataModelImpl.java:337)
at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelImpl.internalSetProperty(DataModelImpl.java:183)
at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelImpl.setProperty(DataModelImpl.java:172)
at org.eclipse.wst.web.ui.internal.wizards.DataModelFacetCreationWizardPage$5.run(DataModelFacetCreationWizardPage.java:411)