In my MDI application, the following is being fired off which is causing the child form to appear again in the MDI. At the point of catching VisibleChanged in the child form, I can see Visible has been set to True at this point.

Appears to stem from UltraWinEditors.TextEditorControlBase.LayoutToolStripOwningOverflow()

Any idea how I can switch this off? What is it doing?

>    myForm.myForm_VisibleChanged(object sender, System.EventArgs e) Line 4362    C#
     System.Windows.Forms.dll!System.Windows.Forms.Control.OnVisibleChanged(System.EventArgs e) + 0x1d8 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Form.OnVisibleChanged(System.EventArgs e) + 0x6d bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.WmShowWindow(ref System.Windows.Forms.Message m) + 0x193 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x39b bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Form.WndProc(ref System.Windows.Forms.Message m) + 0x18b bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x14c bytes    
     [Native to Managed Transition]    
     [Managed to Native Transition]    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.CreateHandle(System.Windows.Forms.CreateParams cp) + 0x479 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.CreateHandle() + 0x28f bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Form.CreateHandle() + 0x296 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.Handle.get() + 0x68 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.RectangleToClient(System.Drawing.Rectangle r) + 0xba bytes    
     System.Windows.Forms.dll!System.Windows.Forms.ScrollableControl.ScrollToControl(System.Windows.Forms.Control activeControl) + 0x148 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.ScrollableControl.ScrollControlIntoView(System.Windows.Forms.Control activeControl) + 0xd9 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.ScrollActiveControlIntoView() + 0x42 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.ScrollableControl.OnLayout(System.Windows.Forms.LayoutEventArgs levent) + 0x48 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Form.OnLayout(System.Windows.Forms.LayoutEventArgs levent) + 0x3c bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.PerformLayout(System.Windows.Forms.LayoutEventArgs args) + 0x162 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.PerformLayout(System.Windows.Forms.LayoutEventArgs args) + 0x317 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.PerformLayout() + 0x19 bytes    
     Infragistics4.Win.UltraWinEditors.v13.1.dll!Infragistics.Win.UltraWinEditors.TextEditorControlBase.LayoutToolStripOwningOverflow() + 0x124 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) + 0xef bytes    
     mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x285 bytes    
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x9 bytes    
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x57 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) + 0x113 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() + 0x10c bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x2aa bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x15a bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) + 0x220 bytes    
     Infragistics4.Win.UltraWinEditors.v13.1.dll!Infragistics.Win.UltraWinEditors.TextEditorControlBase.TextEditorControlBaseNativeWindow.WndProc(ref System.Windows.Forms.Message msg) + 0x880 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x15a bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) + 0x220 bytes    
     Infragistics4.Win.v13.1.dll!Infragistics.Win.UltraWinEditors.EditorButtonControlBase.EditorButtonControlBaseNativeWindow.WndProc(ref System.Windows.Forms.Message msg) + 0x7f bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x15a bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) + 0x220 bytes    
     Infragistics4.Win.v13.1.dll!Infragistics.Win.UIAutomation.UiaProviderControlNativeWindow.WndProc(ref System.Windows.Forms.Message msg) + 0x9b bytes    
     System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x14c bytes    
     [Native to Managed Transition]    
     [Managed to Native Transition]    
     System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(System.IntPtr dwComponentID, int reason, int pvLoopData) + 0x681 bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason, System.Windows.Forms.ApplicationContext context) + 0x57c bytes    
     System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x6f bytes    
     CMS.exe!CMS.CMSControl.main(String() args) Line 601 + 0x9 bytes    Basic
     [Native to Managed Transition]    
     [Managed to Native Transition]    
     Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() + 0x5a bytes    
     mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x285 bytes    
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx) + 0x9 bytes    
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x57 bytes    
     mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x51 bytes    
     [Native to Managed Transition]