diff -r 91111c86b013 editor.lib/src/org/netbeans/editor/GuardedDocument.java
--- a/editor.lib/src/org/netbeans/editor/GuardedDocument.java	Thu Sep 24 20:15:20 2009 +0200
+++ b/editor.lib/src/org/netbeans/editor/GuardedDocument.java	Fri Sep 25 12:38:21 2009 +0200
@@ -383,12 +383,7 @@
 
         Style style =  styles.addStyle(styleName, parent);
         if (findLayer(layerName) == null) { // not created by default
-            try {
-                extWriteLock();
-                addStyledLayer(layerName, style);
-            } finally {
-                extWriteUnlock();
-            }
+            addStyledLayer(layerName, style);
         }
         return style;
     }
@@ -438,7 +433,6 @@
      */
     public void setLogicalStyle(int pos, Style s) {
         try {
-            extWriteLock();
             pos = Utilities.getRowStart(this, pos);
             String layerName = (String)stylesToLayers.get(s.getName());
             // remove all applied styles
@@ -458,8 +452,6 @@
                 pos, 0, DocumentEvent.EventType.CHANGE, null)); // enough to say length 0
         } catch (BadLocationException e) {
             // do nothing for invalid positions
-        } finally {
-            extWriteUnlock();
         }
     }