diff --git a/components/synedit/syncompletion.pas b/components/synedit/syncompletion.pas
index 47c10aa65d..cfad82d03c 100644
--- a/components/synedit/syncompletion.pas
+++ b/components/synedit/syncompletion.pas
@@ -455,6 +455,8 @@ end;
 
 procedure TSynBaseCompletionForm.Deactivate;
 begin
+  // completion box lost focus
+  // this can happen when a hint window is clicked => ToDo
   Visible := False;
   {$IFDEF SYN_LAZARUS}
   FHint.Visible := False;
diff --git a/ide/sourceeditor.pp b/ide/sourceeditor.pp
index 9eb41fd742..076177dd3c 100644
--- a/ide/sourceeditor.pp
+++ b/ide/sourceeditor.pp
@@ -2411,7 +2411,9 @@ var
   TextS, TextS2: String;
   LogCaret: TPoint;
 begin
-  //debugln('TSourceEditor.StartIdentCompletion');
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceEditor.StartIdentCompletion JumpToError: ',JumpToError]);
+  {$ENDIF}
   if (FEditor.ReadOnly) or (CurrentCompletionType<>ctNone) then exit;
   SourceNotebook.fIdentCompletionJumpToError:=JumpToError;
   SourceNotebook.CreateCompletionForm;
@@ -2433,6 +2435,9 @@ begin
   end;
   aCompletion.Editor:=FEditor;
   aCompletion.Execute(TextS2,P.X,P.Y);
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceEditor.StartIdentCompletion END aCompletion.TheForm.Visible=',aCompletion.TheForm.Visible]);
+  {$ENDIF}
 end;
 
 procedure TSourceEditor.IncreaseIgnoreCodeBufferLock;
@@ -3160,6 +3165,9 @@ procedure TSourceNotebook.CreateCompletionForm;
 var
   i: Integer;
 begin
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceNotebook.CreateCompletionForm START ',dbgsname(aCompletion)]);
+  {$ENDIF}
   // completion form
   if aCompletion<>nil then exit;
   aCompletion := TSynCompletion.Create(Self);
@@ -3676,7 +3684,10 @@ var
   Editor: TSynEdit;
   OldCompletionType: TCompletionType;
 Begin
-  if CurCompletionControl=nil then 
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceNotebook.ccComplete START']);
+  {$ENDIF}
+  if CurCompletionControl=nil then
   begin
     Value := SourceValue;
     exit;
@@ -3756,6 +3767,10 @@ Procedure TSourceNotebook.ccCancel(Sender: TObject);
 // user cancels completion form
 begin
   if CurCompletionControl=nil then exit;
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceNotebook.ccCancel START']);
+  //debugln(GetStackTrace(true));
+  {$ENDIF}
   DeactivateCompletionForm;
 end;
 
@@ -3769,6 +3784,9 @@ var
   NewStr: String;
   CurEdit: TSynEdit;
 Begin
+  {$IFDEF VerboseIDECompletionBox}
+  debugln(['TSourceNotebook.ccExecute START']);
+  {$ENDIF}
   CurCompletionControl := Sender as TSynCompletion;
   S := TStringList.Create;
   Prefix := CurCompletionControl.CurrentString;
diff --git a/lcl/forms.pp b/lcl/forms.pp
index 277e163cbd..c1c61f5942 100644
--- a/lcl/forms.pp
+++ b/lcl/forms.pp
@@ -460,6 +460,7 @@ type
     FFormBorderStyle: TFormBorderStyle;
     FActionLists: TList;
     procedure CMShowingChanged(var Message: TLMessage); message CM_SHOWINGCHANGED;
+    procedure DoShowWindow; dynamic;
     procedure Activate; dynamic;
     procedure ActiveChanged; dynamic;
     procedure BeginFormUpdate;
@@ -724,6 +725,8 @@ type
     procedure SetAutoHide(Value : Boolean);
     procedure AutoHideHint(Sender : TObject);
     procedure SetHideInterval(Value : Integer);
+  protected
+    procedure DoShowWindow; override;
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
diff --git a/lcl/include/customform.inc b/lcl/include/customform.inc
index 8001971a10..ec54846b01 100644
--- a/lcl/include/customform.inc
+++ b/lcl/include/customform.inc
@@ -392,8 +392,6 @@ end;
   ShowWindow event handler.
  ------------------------------------------------------------------------------}
 procedure TCustomForm.WMShowWindow(var message: TLMShowWindow);
-var
-  NewFocusControl: TWinControl;
 begin
   {$IFDEF VerboseFocus}
   DbgOut('TCustomForm.WMShowWindow A ',Name,':'+ClassName+' fsShowing='+dbgs(fsShowing in FFormState)+' Msg.Show='+dbgs(Message.Show));
@@ -411,29 +409,7 @@ begin
     if Message.Status = 0 then
     begin
       if Message.Show then begin
-        if (ActiveControl = nil) and (not (csDesigning in ComponentState))
-        and (Parent=nil) then begin
-          // automatically choose a control to focus
-          {$IFDEF VerboseFocus}
-          DebugLn('TCustomForm.WMShowWindow ',DbgSName(Self),' Set ActiveControl := ',DbgSName(FindDefaultForActiveControl));
-          {$ENDIF}
-          ActiveControl := FindDefaultForActiveControl;
-        end;
-        if ([csLoading,csDestroying]*ComponentState=[])
-        and (Parent=nil) then begin
-          NewFocusControl:=FActiveControl;
-          if (NewFocusControl=nil)
-          or (not NewFocusControl.CanFocus)
-          then
-            NewFocusControl:=Self;
-          if NewFocusControl.HandleAllocated and NewFocusControl.IsVisible
-          then begin
-            {$IFDEF VerboseFocus}
-            DebugLn('TCustomForm.WMShowWindow ',DbgSName(Self),' SetFocus NewFocusControl=',DbgSName(NewFocusControl),' FActiveControl=',DbgSName(FActiveControl));
-            {$ENDIF}
-            LCLIntf.SetFocus(NewFocusControl.Handle);
-          end;
-        end;
+        DoShowWindow;
       end;
     end;
   finally
@@ -482,6 +458,36 @@ begin
     DoHide;
   inherited;
 end;
+
+procedure TCustomForm.DoShowWindow;
+var
+  NewFocusControl: TWinControl;
+begin
+  if (ActiveControl = nil) and (not (csDesigning in ComponentState))
+  and (Parent=nil) then begin
+    // automatically choose a control to focus
+    {$IFDEF VerboseFocus}
+    DebugLn('TCustomForm.DoShowWindow ',DbgSName(Self),' Set ActiveControl := ',DbgSName(FindDefaultForActiveControl));
+    {$ENDIF}
+    ActiveControl := FindDefaultForActiveControl;
+  end;
+  if ([csLoading,csDestroying]*ComponentState=[])
+  and (Parent=nil) then begin
+    NewFocusControl:=FActiveControl;
+    if (NewFocusControl=nil)
+    or (not NewFocusControl.CanFocus)
+    then
+      NewFocusControl:=Self;
+    if NewFocusControl.HandleAllocated and NewFocusControl.IsVisible
+    then begin
+      {$IFDEF VerboseFocus}
+      DebugLn('TCustomForm.DoShowWindow ',DbgSName(Self),' SetFocus NewFocusControl=',DbgSName(NewFocusControl),' FActiveControl=',DbgSName(FActiveControl));
+      {$ENDIF}
+      LCLIntf.SetFocus(NewFocusControl.Handle);
+    end;
+  end;
+end;
+
 {------------------------------------------------------------------------------
   Method: TCustomForm.Activate
   Params: none
diff --git a/lcl/include/hintwindow.inc b/lcl/include/hintwindow.inc
index ff6ae38c8b..051736a3e9 100644
--- a/lcl/include/hintwindow.inc
+++ b/lcl/include/hintwindow.inc
@@ -59,6 +59,18 @@ Begin
     TCustomTimer(FAutoHideTimer).Interval := FHideInterval;
 end;
 
+procedure THintWindow.DoShowWindow;
+begin
+  if (ActiveControl = nil) and (not (csDesigning in ComponentState))
+  and (Parent=nil) then begin
+    // automatically choose a control to focus
+    {$IFDEF VerboseFocus}
+    DebugLn('THintWindow.WMShowWindow ',DbgSName(Self),' Set ActiveControl := ',DbgSName(FindDefaultForActiveControl));
+    {$ENDIF}
+    ActiveControl := FindDefaultForActiveControl;
+  end;
+end;
+
 procedure THintWindow.SetAutoHide(Value : Boolean);
 Begin
   FAutoHide := Value;
diff --git a/lcl/interfaces/gtk/gtkwinapi.inc b/lcl/interfaces/gtk/gtkwinapi.inc
index 54e2f74b11..790312d679 100644
--- a/lcl/interfaces/gtk/gtkwinapi.inc
+++ b/lcl/interfaces/gtk/gtkwinapi.inc
@@ -8620,6 +8620,7 @@ begin
   {$IfDef VerboseFocus}
   DebugLn('');
   debugln('[TGtkWidgetSet.SetFocus] A hWnd=',GetWidgetDebugReport(Widget));
+  //DebugLn(getStackTrace(true));
   {$EndIf}
 
   // return the old focus handle