diff --git a/trunk/ProcessHacker/Components/ThreadList.cs b/trunk/ProcessHacker/Components/ThreadList.cs
index 1591b801b..094ecdfed 100644
--- a/trunk/ProcessHacker/Components/ThreadList.cs
+++ b/trunk/ProcessHacker/Components/ThreadList.cs
@@ -122,13 +122,20 @@ namespace ProcessHacker.Components
                     catch
                     { }
 
-                    try
+                    if (!_provider.Symbols.Busy)
                     {
-                        _provider.Symbols.GetSymbolFromAddress(_provider.Dictionary[tid].StartAddressI, out fileName);
-                        fileModule.Text = fileName;
-                        fileModule.Enabled = true;
+                        try
+                        {
+                            _provider.Symbols.GetSymbolFromAddress(_provider.Dictionary[tid].StartAddressI, out fileName);
+                            fileModule.Text = fileName;
+                            fileModule.Enabled = true;
+                        }
+                        catch
+                        {
+                            fileModule.Enabled = false;
+                        }
                     }
-                    catch
+                    else
                     {
                         fileModule.Enabled = false;
                     }
diff --git a/trunk/ProcessHacker/Forms/ProcessWindow.cs b/trunk/ProcessHacker/Forms/ProcessWindow.cs
index 537d282ff..933581af1 100644
--- a/trunk/ProcessHacker/Forms/ProcessWindow.cs
+++ b/trunk/ProcessHacker/Forms/ProcessWindow.cs
@@ -82,6 +82,9 @@ namespace ProcessHacker
                 this.Icon = Program.HackerWindow.Icon;
 
             Program.PWindows.Add(_pid, this);
+
+            this.InitializeSubControls();
+            this.FixTabs();
         }
 
         public MenuItem WindowMenuItem
@@ -152,10 +155,41 @@ namespace ProcessHacker
         {
             if (_isFirstPaint)
             {
+                _isFirstPaint = false;
                 this.LoadStage1();
             }
+        }
 
-            _isFirstPaint = false;
+        private void FixTabs()
+        {
+            if (_pid < 0)
+            {
+                // this "process" is probably DPCs or Interrupts, so we won't try to load any more information
+                buttonEditDEP.Enabled = false;
+                buttonEditProtected.Enabled = false;
+                buttonInspectParent.Enabled = false;
+                buttonInspectPEB.Enabled = false;
+
+                if (fileCurrentDirectory.Text != "")
+                    fileCurrentDirectory.Enabled = false;
+
+                if (_pid != 4)
+                    fileImage.Enabled = false;
+
+                buttonSearch.Enabled = false;
+                buttonTerminate.Enabled = false;
+
+                // remove tab controls not relevant to DPCs/Interrupts
+                tabControl.TabPages.Remove(tabHandles);
+                tabControl.TabPages.Remove(tabMemory);
+                tabControl.TabPages.Remove(tabModules);
+                tabControl.TabPages.Remove(tabServices);
+                tabControl.TabPages.Remove(tabThreads);
+                tabControl.TabPages.Remove(tabToken);
+                if (tabControl.TabPages.Contains(tabJob))
+                    tabControl.TabPages.Remove(tabJob);
+                tabControl.TabPages.Remove(tabEnvironment);
+            }
         }
 
         private void LoadStage1()
@@ -193,34 +227,6 @@ namespace ProcessHacker
             { }
 
             this.UpdateProcessProperties();
-            
-            if (_pid < 0)
-            {
-                // this "process" is probably DPCs or Interrupts, so we won't try to load any more information
-                buttonEditDEP.Enabled = false;
-                buttonEditProtected.Enabled = false;
-                buttonInspectParent.Enabled = false;
-                buttonInspectPEB.Enabled = false;
-
-                if (fileCurrentDirectory.Text != "")
-                    fileCurrentDirectory.Enabled = false;
-
-                if (_pid != 4)
-                    fileImage.Enabled = false;
-
-                buttonSearch.Enabled = false;
-                buttonTerminate.Enabled = false;
-
-                // remove tab controls not relevant to DPCs/Interrupts
-                tabControl.TabPages.Remove(tabHandles);
-                tabControl.TabPages.Remove(tabMemory);
-                tabControl.TabPages.Remove(tabModules);
-                tabControl.TabPages.Remove(tabServices);
-                tabControl.TabPages.Remove(tabThreads);
-                tabControl.TabPages.Remove(tabToken);
-                tabControl.TabPages.Remove(tabJob);
-                tabControl.TabPages.Remove(tabEnvironment);
-            }
 
             if (_pid == 0)
                 textFileDescription.Text = "System Idle Process";
@@ -250,8 +256,6 @@ namespace ProcessHacker
         {
             this.SuspendLayout();
 
-            this.InitializeSubControls();
-
             try
             {
                 this.InitializeProviders();
diff --git a/trunk/ProcessHacker/Program/Program.cs b/trunk/ProcessHacker/Program/Program.cs
index 808fc8aef..6ff49f56d 100644
--- a/trunk/ProcessHacker/Program/Program.cs
+++ b/trunk/ProcessHacker/Program/Program.cs
@@ -71,7 +71,7 @@ namespace ProcessHacker
         public static Dictionary<string, PEWindow> PEWindows = new Dictionary<string, PEWindow>();
         public static Dictionary<string, Thread> PEThreads = new Dictionary<string, Thread>();
 
-        public const bool PWindowsThreaded = true;
+        public const bool PWindowsThreaded = false;
         public static Dictionary<int, ProcessWindow> PWindows = new Dictionary<int, ProcessWindow>();
         public static Dictionary<int, Thread> PThreads = new Dictionary<int, Thread>();
 
diff --git a/trunk/ProcessHacker/Symbols/Symbols.cs b/trunk/ProcessHacker/Symbols/Symbols.cs
index 4445e8385..c4bbfedc6 100644
--- a/trunk/ProcessHacker/Symbols/Symbols.cs
+++ b/trunk/ProcessHacker/Symbols/Symbols.cs
@@ -112,6 +112,22 @@ namespace ProcessHacker.Symbols
 
         public bool PreloadModules { get; set; }
 
+        public bool Busy
+        {
+            get
+            {
+                if (!Monitor.TryEnter(_callLock))
+                {
+                    return true;
+                }
+                else
+                {
+                    Monitor.Exit(_callLock);
+                    return false;
+                }
+            }
+        }
+
         public static void ShowWarning(IWin32Window window, bool force)
         {
             if (Properties.Settings.Default.DbgHelpWarningShown && !force)