title: identifier highlighting and jumping stopped working
body: <p>I've had this problem come and go between different workspaces...</p>
  
  <p>At some point identifier highlighting (with the cursor on an identifier, all other occurrences in scope get highlighted) and command-click on an identifier to jump to its definition both stopped working in some files.</p>
  
  <p>These are java source files.  And there are no errors in the file or the file's project.  This is in the java perspective.</p>
  
  <p>The problem is definitely not eclipse-wide or workspace-wide.  I can switch between java files and some work, some do not.  It may be project specific (a quick test shows it not working on two java files in the same project, but working on a java file from another project).</p>
  
  <p>Thank you!
  Matt</p>