Eclipse插件PDT安装失败，求支援！

报如下错：

Cannot complete the install because one or more required items could not be found. 
  Software being installed: PHP Development Tools (PDT) 3.1.2.201212211235 (org.eclipse.php.feature.group 3.1.2.201212211235) 
   Missing requirement: PDT Core Plug-in 3.1.2.201212211235 (org.eclipse.php.core 3.1.2.201212211235) requires 'bundle org.eclipse.dltk.core.index.sql [4.0.0,5.0.0)' but it could not be found 
   Cannot satisfy dependency: 
     From: PHP Development Tools (PDT) 3.1.2.201212211235 (org.eclipse.php.feature.group 3.1.2.201212211235) 

    To: org.eclipse.php.core [3.1.2.201212211235] 

说明：我已经安装了 DLTK，开始是安装的2.0，报同样的错，后来卸载装了1.0的，还是报错。。。郁闷中，以前也遇到过这个问题，后来不知怎么的就解决了。。。