eclipse安装windowsbuilder时候出现问题：Cannot complete the install be

eclipse安装windowsbuilder时候出现问题：Cannot complete the install because one or more ...（如下）
Cannot complete the install because one or more required items could not be found.
Software being installed: SWT Designer XWT Support (requires Eclipse WTP/WST) 1.5.2.r37x201302112106 (org.eclipse.wb.xwt.feature.feature.group 1.5.2.r37x201302112106)
Missing requirement: WindowBuilder Core for XML GUI's 1.5.2.r37x201302111919 (org.eclipse.wb.core.xml 1.5.2.r37x201302111919) requires 'bundle org.eclipse.wst.sse.core 0.0.0' but it could not be found
Cannot satisfy dependency:
From: SWT Designer XWT Support 1.5.2.r37x201302112106 (org.eclipse.wb.xwt 1.5.2.r37x201302112106)
To: bundle org.eclipse.wb.core.xml 0.0.0
Cannot satisfy dependency:
From: SWT Designer XWT Support (requires Eclipse WTP/WST) 1.5.2.r37x201302112106 (org.eclipse.wb.xwt.feature.feature.group 1.5.2.r37x201302112106)
To: org.eclipse.wb.xwt [1.5.2.r37x201302112106]
请问怎么解决?