diff --git a/java/debugger/impl/src/com/intellij/debugger/actions/CompareValueWithClipboardAction.java b/java/debugger/impl/src/com/intellij/debugger/actions/CompareValueWithClipboardAction.java
index ab449e0eecc2..2d27120d1ab0 100644
--- a/java/debugger/impl/src/com/intellij/debugger/actions/CompareValueWithClipboardAction.java
+++ b/java/debugger/impl/src/com/intellij/debugger/actions/CompareValueWithClipboardAction.java
@@ -20,6 +20,7 @@ import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.diff.*;
 import com.intellij.openapi.ide.CopyPasteManager;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.SystemInfo;
 
 import java.awt.datatransfer.DataFlavor;
 import java.awt.datatransfer.Transferable;
@@ -50,6 +51,11 @@ public class CompareValueWithClipboardAction extends BaseValueAction {
       };
     }
 
+    @Override
+    public boolean isSafeToCallFromUpdate() {
+      return !SystemInfo.isMac;
+    }
+
     public DiffContent[] getContents() {
       if (myContents != null) return myContents;
       DiffContent clipboardContent = createClipboardContent();
diff --git a/platform/platform-api/src/com/intellij/openapi/diff/DiffRequest.java b/platform/platform-api/src/com/intellij/openapi/diff/DiffRequest.java
index 11e83b66bdab..9e3b88c39dc6 100644
--- a/platform/platform-api/src/com/intellij/openapi/diff/DiffRequest.java
+++ b/platform/platform-api/src/com/intellij/openapi/diff/DiffRequest.java
@@ -51,6 +51,10 @@ public abstract class DiffRequest {
   public void setGroupKey(@NonNls String groupKey) { myGroupKey = groupKey; }
   public Project getProject() { return myProject; }
 
+  public boolean isSafeToCallFromUpdate() {
+    return true;
+  }
+  
   /**
    * @return contents to compare
    */
diff --git a/platform/platform-impl/src/com/intellij/openapi/diff/actions/BaseDiffAction.java b/platform/platform-impl/src/com/intellij/openapi/diff/actions/BaseDiffAction.java
index ee85cd6296ab..bd441e1ed8be 100644
--- a/platform/platform-impl/src/com/intellij/openapi/diff/actions/BaseDiffAction.java
+++ b/platform/platform-impl/src/com/intellij/openapi/diff/actions/BaseDiffAction.java
@@ -49,9 +49,10 @@ abstract class BaseDiffAction extends AnAction implements PreloadableAction, Dum
 
   public void update(AnActionEvent e) {
     DiffRequest diffData = getDiffData(e.getDataContext());
-    boolean enabled;
-    if (diffData == null || diffData.getContents() == null) enabled = false;
-    else enabled = DiffManager.getInstance().getDiffTool().canShow(diffData);
+    
+    boolean enabled = diffData != null &&
+                      (!diffData.isSafeToCallFromUpdate() || (diffData.getContents() != null && DiffManager.getInstance().getDiffTool().canShow(diffData)));
+
     Presentation presentation = e.getPresentation();
     presentation.setEnabled(enabled);
     if (enabled) presentation.setVisible(true);
diff --git a/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareClipboardWithSelection.java b/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareClipboardWithSelection.java
index 12e49e3c18a6..19c558da157c 100644
--- a/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareClipboardWithSelection.java
+++ b/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareClipboardWithSelection.java
@@ -24,6 +24,7 @@ import com.intellij.openapi.editor.SelectionModel;
 import com.intellij.openapi.fileEditor.FileEditorManager;
 import com.intellij.openapi.ide.CopyPasteManager;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.TextRange;
 import org.jetbrains.annotations.Nullable;
 
@@ -59,6 +60,11 @@ public class CompareClipboardWithSelection extends BaseDiffAction {
       };
     }
 
+    @Override
+    public boolean isSafeToCallFromUpdate() {
+      return !SystemInfo.isMac;
+    }
+
     public DiffContent[] getContents() {
       if (myContents != null) return myContents;
       DiffContent clipboardContent = createClipboardContent();
diff --git a/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareFiles.java b/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareFiles.java
index 894e6b7fca99..0c84ed3dc329 100644
--- a/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareFiles.java
+++ b/platform/platform-impl/src/com/intellij/openapi/diff/actions/CompareFiles.java
@@ -44,7 +44,7 @@ public class CompareFiles extends BaseDiffAction {
       presentation.setVisible(false);
       return;
     }
-    final boolean canShow = DiffManager.getInstance().getDiffTool().canShow(diffRequest);
+    final boolean canShow = !diffRequest.isSafeToCallFromUpdate() || DiffManager.getInstance().getDiffTool().canShow(diffRequest);
     if (ActionPlaces.isPopupPlace(e.getPlace())) {
       presentation.setVisible(canShow);      
     }