println and classOf[] are marked red unless prefixed with Predef

I noticed that predef methods like println and classOf are marked as red unless I explicitly put Predef.println() or Predef.classOf[].  For example, in this code there are two red tokens:

object Tester extends App{
  println("hello")                                   //println is red
  Predef.println(classOf[String])            //classOf is red
  Predef.println(Predef.classOf[String])  //no red code
}

the first println and the first classOf are marked in red.  Is this a problem for others?  How can this be fixed?  I am using IDEA 10.5.2 with Scala plugin 0.4.1440 on Win7 x64.

Thanks!
Sam