Scala plugin doesn't highlight errors.  

Notes:

1) fsc is working from command line

2) Some other features are working.  For example, syntax coloring, code completion, formatting, go to declaration, outline navigator

3) The following exception appears once in IDE log

java.lang.IllegalStateException: You are trying to access file: compiler.properties from the default package. Please see 
http://www.netbeans.org/download/dev/javadoc/org-openide-modules/org/openide/modules/doc-
files/classpath.html#default_package
        at org.netbeans.ProxyClassLoader.printDefaultPackageWarning(ProxyClassLoader.java:578)
        at org.netbeans.ProxyClassLoader.getResource(ProxyClassLoader.java:343)
        at java.lang.ClassLoader.getResourceAsStream(ClassLoader.java:1168)
        at java.lang.Class.getResourceAsStream(Class.java:2030)
        at scala.tools.nsc.Properties$.<init>(Properties.scala:21)
        at scala.tools.nsc.Properties$.<clinit>(Properties.scala)
        at scala.tools.nsc.Settings.guessedScalaBootClassPath(Settings.scala:63)
        at scala.tools.nsc.Settings.<init>(Settings.scala:34)
        at scala.tools.nsc.Settings.<init>(Settings.scala:14)
        at org.netbeans.modules.scala.editing.ScalaGlobal.getGlobal(ScalaGlobal.java:163)
        at org.netbeans.modules.scala.editing.ScalaParser.parseBuffer(ScalaParser.java:552)
        at org.netbeans.modules.scala.editing.ScalaParser.parse(ScalaParser.java:112)
        at org.netbeans.modules.parsing.impl.SourceCache.getResult(SourceCache.java:198)
        at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:655)
        ....