diff --git a/src/actors/scala/actors/Actor.scala b/src/actors/scala/actors/Actor.scala
index 015ec917b65d..43d1f7c70732 100644
--- a/src/actors/scala/actors/Actor.scala
+++ b/src/actors/scala/actors/Actor.scala
@@ -11,6 +11,7 @@
 package scala.actors
 
 import scala.compat.Platform
+import scala.util.control.ControlException
 import java.util.{Timer, TimerTask}
 import java.util.concurrent.ExecutionException
 
@@ -881,7 +882,7 @@ case class Exit(from: AbstractActor, reason: AnyRef)
  * @version 0.9.8
  * @author Philipp Haller
  */
-private[actors] class SuspendActorException extends Throwable {
+private[actors] class SuspendActorException extends Throwable with ControlException {
   /*
    * For efficiency reasons we do not fill in
    * the execution stack trace.
diff --git a/src/actors/scala/actors/Reaction.scala b/src/actors/scala/actors/Reaction.scala
index fee697b6cbc9..c8e19400eb5f 100644
--- a/src/actors/scala/actors/Reaction.scala
+++ b/src/actors/scala/actors/Reaction.scala
@@ -11,9 +11,10 @@
 
 package scala.actors
 
+import scala.util.control.ControlException
 import java.lang.{InterruptedException, Runnable}
 
-private[actors] class KillActorException extends Throwable {
+private[actors] class KillActorException extends Throwable with ControlException {
   /*
    * For efficiency reasons we do not fill in
    * the execution stack trace.
diff --git a/src/actors/scala/actors/SchedulerService.scala b/src/actors/scala/actors/SchedulerService.scala
index 1826a153da91..78abb97962e7 100644
--- a/src/actors/scala/actors/SchedulerService.scala
+++ b/src/actors/scala/actors/SchedulerService.scala
@@ -10,6 +10,7 @@
 
 package scala.actors
 
+import scala.util.control.ControlException
 import java.lang.{Runnable, Thread, InterruptedException}
 
 /**
@@ -95,7 +96,7 @@ abstract class SchedulerService(daemon: Boolean) extends Thread with ActorGC {
  * @version 0.9.8
  * @author Philipp Haller
  */
-private[actors] class QuitException extends Throwable {
+private[actors] class QuitException extends Throwable with ControlException {
   /*
    For efficiency reasons we do not fill in
    the execution stack trace.
diff --git a/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala b/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
index a8f685385342..d247134fd6fd 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/MarkupParsers.scala
@@ -7,6 +7,7 @@
 package scala.tools.nsc.ast.parser
 
 import scala.collection.mutable
+import scala.util.control.ControlException
 import scala.tools.nsc.util.{Position,NoPosition,SourceFile,CharArrayReader}
 import scala.xml.{Text, TextBuffer}
 import SourceFile.{SU,LF}
@@ -18,15 +19,15 @@ import scala.annotation.switch
  *  @version 1.0
  */
 trait MarkupParsers {self: Parsers =>
-  case object MissingEndTagException extends RuntimeException {
+  case object MissingEndTagException extends RuntimeException with ControlException {
     override def getMessage = "start tag was here: "
   }
 
-  case object ConfusedAboutBracesException extends RuntimeException {
+  case object ConfusedAboutBracesException extends RuntimeException with ControlException {
     override def getMessage = " I encountered a '}' where I didn't expect one, maybe this tag isn't closed <"
   }
 
-  case object TruncatedXML extends RuntimeException {
+  case object TruncatedXML extends RuntimeException with ControlException {
     override def getMessage = "input ended while parsing XML"
   }
 
diff --git a/src/compiler/scala/tools/nsc/interactive/CompilerControl.scala b/src/compiler/scala/tools/nsc/interactive/CompilerControl.scala
index d264632bd53a..0782639ac567 100644
--- a/src/compiler/scala/tools/nsc/interactive/CompilerControl.scala
+++ b/src/compiler/scala/tools/nsc/interactive/CompilerControl.scala
@@ -1,6 +1,7 @@
 package scala.tools.nsc.interactive
 
 import scala.concurrent.SyncVar
+import scala.util.control.ControlException
 import scala.tools.nsc.io.AbstractFile
 import scala.tools.nsc.util.{SourceFile, Position, WorkScheduler}
 import scala.tools.nsc.symtab._
@@ -104,8 +105,8 @@ trait CompilerControl { self: Global =>
 
   // ---------------- Interpreted exeptions -------------------
 
-  class CancelActionReq extends Exception
-  class FreshRunReq extends Exception
-  class ShutdownReq extends Exception
+  class CancelActionReq extends Exception with ControlException
+  class FreshRunReq extends Exception with ControlException
+  class ShutdownReq extends Exception with ControlException
 
 }
diff --git a/src/compiler/scala/tools/nsc/interactive/Global.scala b/src/compiler/scala/tools/nsc/interactive/Global.scala
index 51ba19951e3e..72415b5d7bd9 100755
--- a/src/compiler/scala/tools/nsc/interactive/Global.scala
+++ b/src/compiler/scala/tools/nsc/interactive/Global.scala
@@ -4,6 +4,7 @@ import java.io.{ PrintWriter, StringWriter }
 
 import scala.collection.mutable.{LinkedHashMap, SynchronizedMap}
 import scala.concurrent.SyncVar
+import scala.util.control.ControlException
 import scala.tools.nsc.io.AbstractFile
 import scala.tools.nsc.util.{SourceFile, Position, RangePosition, OffsetPosition, NoPosition, WorkScheduler}
 import scala.tools.nsc.reporters._
@@ -77,11 +78,19 @@ self =>
         throw new TyperResult(located)
       }
       val typerRun = currentTyperRun
-      pollForWork()
-      if (typerRun != currentTyperRun) {
-        integrateNew()
-        throw new FreshRunReq
-      }
+
+      while(true)
+        try {
+          pollForWork()
+          if (typerRun == currentTyperRun)
+            return
+
+          integrateNew()
+          throw new FreshRunReq
+        } catch {
+          case ex : ValidateError => // Ignore, this will have been reported elsewhere
+          case t : Throwable => throw t
+        }
     }
   }
 
@@ -421,9 +430,8 @@ self =>
     }
   }
 
-  class TyperResult(val tree: Tree) extends Exception
+  class TyperResult(val tree: Tree) extends Exception with ControlException
 
   assert(globalPhase.id == 0)
-
 }
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 7565b20c5697..ce16b5500198 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -7,6 +7,7 @@
 package scala.tools.nsc.typechecker
 import scala.tools.nsc.util.{Position, NoPosition}
 import scala.collection.mutable.ListBuffer
+import scala.util.control.ControlException
 import symtab.Flags._
 
 /** This trait ...
@@ -77,7 +78,7 @@ trait Infer {
   //todo: remove comments around following privates; right now they cause an IllegalAccess
   // error when built with scalac
 
-  /*private*/ class NoInstance(msg: String) extends RuntimeException(msg)
+  /*private*/ class NoInstance(msg: String) extends RuntimeException(msg) with ControlException
 
   /*private*/ class DeferredNoInstance(getmsg: () => String) extends NoInstance("") {
     override def getMessage(): String = getmsg()
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index f576c17ad162..b1ed6da20895 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -11,7 +11,9 @@
 package scala.tools.nsc.typechecker
 
 import scala.collection.mutable.{HashMap, ListBuffer}
+import scala.util.control.ControlException
 import scala.compat.Platform.currentTime
+import scala.tools.nsc.interactive.RangePositions
 import scala.tools.nsc.util.{HashSet, Position, Set, NoPosition, SourceFile}
 import symtab.Flags._
 import util.HashSet
@@ -3735,7 +3737,6 @@ trait Typers { self: Analyzer =>
      *  @return     ...
      */
     def typed(tree: Tree, mode: Int, pt: Type): Tree = {
-      import scala.tools.nsc.interactive.CompilerControl
 
       def dropExistential(tp: Type): Type = tp match {
         case ExistentialType(tparams, tpe) =>
@@ -3767,7 +3768,7 @@ trait Typers { self: Analyzer =>
         if (phase.id <= currentRun.typerPhase.id) signalDone(context.asInstanceOf[analyzer.Context], tree, result)
         result
       } catch {
-        case ex: CompilerControl#FreshRunReq => throw ex
+        case ex: ControlException => throw ex
         case ex: TypeError =>
           tree.tpe = null
           //Console.println("caught "+ex+" in typed");//DEBUG
diff --git a/src/library/scala/runtime/NonLocalReturnException.scala b/src/library/scala/runtime/NonLocalReturnException.scala
index 7bb7b9934111..2884a0ce9f43 100644
--- a/src/library/scala/runtime/NonLocalReturnException.scala
+++ b/src/library/scala/runtime/NonLocalReturnException.scala
@@ -13,8 +13,9 @@ package scala.runtime
 
 
 import Predef.RuntimeException
+import scala.util.control.ControlException
 
-class NonLocalReturnException[T](val key: AnyRef, val value: T) extends RuntimeException {
+class NonLocalReturnException[T](val key: AnyRef, val value: T) extends RuntimeException with ControlException {
   /*
    * For efficiency reasons we do not fill in
    * the execution stack trace.
diff --git a/src/library/scala/util/control/Breaks.scala b/src/library/scala/util/control/Breaks.scala
index 3315140b6b44..25adf8057315 100755
--- a/src/library/scala/util/control/Breaks.scala
+++ b/src/library/scala/util/control/Breaks.scala
@@ -44,5 +44,5 @@ class Breaks {
 /** A singleton object providing the Break functionality */
 object Breaks extends Breaks
 
-private class BreakException extends RuntimeException
+private class BreakException extends RuntimeException with ControlException
 
diff --git a/src/library/scala/util/control/ControlException.scala b/src/library/scala/util/control/ControlException.scala
new file mode 100644
index 000000000000..4ac7b0ceebad
--- /dev/null
+++ b/src/library/scala/util/control/ControlException.scala
@@ -0,0 +1,39 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2009, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id$
+
+package scala.util.control
+
+/**
+ * A marker trait indicating that the <code>Throwable</code> it is mixed
+ * into is intended for flow control.
+ *
+ * <p>Note that <code>Throwable</code> subclasses which extend this trait
+ * may extend any other <code>Throwable</code> subclass (eg.
+ * <code>RuntimeException</code>) and are not required to extend
+ * <code>Throwable</code> directly.</p>
+ *
+ * <p>Instances of <code>Throwable</code> subclasses marked in
+ * this way should not normally be caught. Where catch-all behaviour is
+ * required <code>ControlException</code>s should be propagated, for
+ * example,</p>
+ *
+ * <pre>
+ *  import scala.util.control.ControlException
+ *
+ *  try {
+ *    // Body might throw arbitrarily
+ * } catch {
+ *   case ce : ControlException => throw ce // propagate
+ *   case t : Exception => log(t)           // log and suppress
+ * </pre>
+ *
+ * @author Miles Sabin
+ */
+trait ControlException extends Throwable