Index: src/java/org/apache/lucene/search/BooleanScorer2.java
===================================================================
--- src/java/org/apache/lucene/search/BooleanScorer2.java	(revision 613923)
+++ src/java/org/apache/lucene/search/BooleanScorer2.java	(working copy)
@@ -175,7 +175,7 @@
   }
 
   private Scorer countingDisjunctionSumScorer(final List scorers,
-                                              int minNrShouldMatch)
+                                              int minNrShouldMatch) throws IOException
   // each scorer from the list counted as a single matcher
   {
     return new DisjunctionSumScorer(scorers, minNrShouldMatch) {
@@ -283,7 +283,7 @@
    * Uses the given required scorer and the prohibitedScorers.
    * @param requiredCountingSumScorer A required scorer already built.
    */
-  private Scorer addProhibitedScorers(Scorer requiredCountingSumScorer)
+  private Scorer addProhibitedScorers(Scorer requiredCountingSumScorer) throws IOException
   {
     return (prohibitedScorers.size() == 0)
           ? requiredCountingSumScorer // no prohibited
Index: src/java/org/apache/lucene/search/DisjunctionSumScorer.java
===================================================================
--- src/java/org/apache/lucene/search/DisjunctionSumScorer.java	(revision 613923)
+++ src/java/org/apache/lucene/search/DisjunctionSumScorer.java	(working copy)
@@ -70,7 +70,7 @@
    * <br>When minimumNrMatchers equals the number of subScorers,
    * it more efficient to use <code>ConjunctionScorer</code>.
    */
-  public DisjunctionSumScorer( List subScorers, int minimumNrMatchers) {
+  public DisjunctionSumScorer( List subScorers, int minimumNrMatchers) throws IOException{
     super(null);
     
     nrScorers = subScorers.size();
@@ -84,12 +84,16 @@
 
     this.minimumNrMatchers = minimumNrMatchers;
     this.subScorers = subScorers;
+    
+    if (scorerDocQueue == null) {
+      initScorerDocQueue();
+    }
   }
   
   /** Construct a <code>DisjunctionScorer</code>, using one as the minimum number
    * of matching subscorers.
    */
-  public DisjunctionSumScorer(List subScorers) {
+  public DisjunctionSumScorer(List subScorers) throws IOException {
     this(subScorers, 1);
   }
 
@@ -140,9 +144,6 @@
   }
 
   public boolean next() throws IOException {
-    if (scorerDocQueue == null) {
-      initScorerDocQueue();
-    }
     return (scorerDocQueue.size() >= minimumNrMatchers)
           && advanceAfterCurrent();
   }
@@ -214,9 +215,6 @@
    * @return true iff there is such a match.
    */
   public boolean skipTo(int target) throws IOException {
-    if (scorerDocQueue == null) {
-      initScorerDocQueue();
-    }
     if (queueSize < minimumNrMatchers) {
       return false;
     }