Index: lucene/src/java/org/apache/lucene/search/cache/IntValuesCreator.java
===================================================================
--- lucene/src/java/org/apache/lucene/search/cache/IntValuesCreator.java	(revision 1065066)
+++ lucene/src/java/org/apache/lucene/search/cache/IntValuesCreator.java	(working copy)
@@ -75,45 +75,50 @@
   }
 
   @Override
-  public synchronized IntValues validate(IntValues entry, IndexReader reader) throws IOException {
+  public IntValues validate(IntValues entry, IndexReader reader) throws IOException {
     boolean ok = false;
-    
-    if( hasOption(OPTION_CACHE_VALUES) ) {
-      ok = true;
-      if( entry.values == null ) {
-        fillIntValues(entry, reader, field);
+
+    synchronized (entry) {
+      if( hasOption(OPTION_CACHE_VALUES) ) {
+        ok = true;
+        if( entry.values == null ) {
+          fillIntValues(entry, reader, field, parser);
+        }
+        else {
+          synchronized (this) {
+            assertSameParser( entry, parser );
+          }
+        }
       }
-      else {
-        assertSameParser( entry, parser );
+      if( hasOption(OPTION_CACHE_BITS) ) {
+        ok = true;
+        if( entry.valid == null ) {
+          fillValidBits(entry, reader, field);
+        }
       }
     }
-    if( hasOption(OPTION_CACHE_BITS) ) {
-      ok = true;
-      if( entry.valid == null ) {
-        fillValidBits(entry, reader, field);
-      }
-    }
     if( !ok ) {
       throw new RuntimeException( "the config must cache values and/or bits" );
     }
     return entry;
   }
 
-  protected void fillIntValues( IntValues vals, IndexReader reader, String field ) throws IOException
+  protected void fillIntValues( IntValues vals, IndexReader reader, String field, IntParser parser ) throws IOException
   {
     if( parser == null ) {
       try {
-        parser = FieldCache.DEFAULT_INT_PARSER;
-        fillIntValues( vals, reader, field );
+        fillIntValues( vals, reader, field, FieldCache.DEFAULT_INT_PARSER );
         return;
       }
       catch (NumberFormatException ne) {
-        vals.parserHashCode = null;
-        parser = FieldCache.NUMERIC_UTILS_INT_PARSER;
-        fillIntValues( vals, reader, field );
+        fillIntValues( vals, reader, field, FieldCache.NUMERIC_UTILS_INT_PARSER );
         return;
       }
     }
+
+    vals.numDocs = 0;
+    vals.numTerms = 0;
+
     setParserAndResetCounts(vals, parser);
     
     Terms terms = MultiFields.getTerms(reader, field);
@@ -161,5 +166,18 @@
     if( vals.valid == null && vals.numDocs < 1 ) {
       vals.valid = new Bits.MatchNoBits( maxDoc );
     }
+
+
+    synchronized (this) {
+      int parserHashCode = parser.hashCode();
+      if( vals.parserHashCode != null && vals.parserHashCode != parserHashCode ) {
+        throw new RuntimeException( "Parser changed in subsequent call.  "
+          +vals.parserHashCode+" != "+parserHashCode + " :: " + parser );
+      }
+      this.parser = parser;
+    }
+
+
+
   }
 }
\ No newline at end of file