Linda,

I have experimented with the ISupportInitialize interface, but without
success.  I have copied some very simplified code below to demonstrate how I
have tried to use this interface.  Note that I am applying the interface to a
derived control instead of the derived form as the original message stated.  
This seemed like the more correct location for my application.

When I try to display the "DerivedForm" with the Forms Designer, the code
that causes the assert is still being reached, even though that code is
called from the EndInit() method and includes a test for DesignMode.

Please look at the code below and let me know if I am missing something.

Thanks,
Dave

===============Code Starts Here=================
  public class MyPanelBase : System.Windows.Forms.UserControl,
ISupportInitialize
  {
     public MyPanelBase()
     {
        InitializeComponent();
     }

     protected virtual void FinishConstruction()
     {
        DoSomethingThatAssertsAtDesignTime();
     }

     // Virtual method overridden by derived class.
     protected virtual void DoSomethingThatAssertsAtDesignTime()
     {}

     public void BeginInit()
     {}

     public void EndInit()
     {
        if ( !this.DesignMode )
        {
           DoSomethingThatAssertsAtDesignTime();
        }
     }
  }

  public class DerivedPanel : MyPanelBase
  {
     public DerivedPanel() : base()
     {
        InitializeComponent();
     }

     protected override void DoSomethingThatAssertsAtDesignTime()
     {
        DoSomethingAtRuntime(); // Causes VS2003 Assert at DesignTime.
     }

     private void InitializeComponent()
     {
        ((System.ComponentModel.ISupportInitialize)(this)).BeginInit();
        this.SuspendLayout();

        // Controls go here...

        ((System.ComponentModel.ISupportInitialize)(this)).EndInit();
        this.ResumeLayout(false);
     }
  }

  public class DerivedForm : ChildFormBase
  {
     private DerivedPanel myDerivedPanel;

     public DerivedForm() : base()
     {
        InitializeComponent();
     }

     private void InitializeComponent()
     {
        this.myDerivedPanel = new DerivedPanel();
       
((System.ComponentModel.ISupportInitialize)(this.myDerivedPanel)).BeginInit();
        this.SuspendLayout();
        //
        // myDerivedPanel
        //
        this.myDerivedPanel.Location = new System.Drawing.Point(0, 50);
        this.myDerivedPanel.Name = "myDerivedPanel";
        this.myDerivedPanel.Size = new System.Drawing.Size(410, 140);
        this.myDerivedPanel.TabIndex = 0;
        //
        // DerivedForm
        //
        this.AutoScaleBaseSize = new System.Drawing.Size(7, 17);
        this.ClientSize = new System.Drawing.Size(432, 643);
        this.Controls.Add(this.myDerivedPanel);
        this.Icon =
((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
        this.Name = "DerivedForm";
        this.Text = "My Form";
       
((System.ComponentModel.ISupportInitialize)(this.myDerivedPanel)).EndInit();
        this.ResumeLayout(false);
     }
  }
===============Code Ends Here==================